金属火圈火坑基础

在此页面上：

• 简介。
• 定义。
• 设计。
• 材料选择。
• 钢板。
• 持平库存。
• 重新利用的材料。
• 厚度。
• 生产能力。
• 总结。

简介。

本文旨在回顾您在为本地或区域分销开发自己的产品线时可能面临的挑战。从概念上讲，这些注意事项适用于许多产品。出于本文的目的，我们将以套件或零售用火环的生产为例。
火环火坑是一种简单的产品，如果设计得当，可以为制造商提供有利可图的收入来源，以满足当地需求和人口统计数据。许多市政当局鼓励或要求在安全的“燃烧季节”期间对“明火”进行某种形式的控制。在太平洋西北地区，这个季节通常会在下雨后开始，当地消防局长决定火灾通过余烬或火花迁移的风险低到足以允许“明火”燃烧。鉴于最近西海岸发生了毁灭性的火灾，未来某个时候可能会同时限制设备和机会。因此，在进行大量投资之前，应该谨慎对待这个市场，并着眼于提高明火的安全性和可靠性，而不仅仅是火环提供的美感。在设计标准方面与当地消防部门合作具有战略价值。要审查的关键设计元素包括优化直径、高度、交叉通风、上边缘处理、艺术元素中未屏蔽切口或开口的最大尺寸，以及是否需要盖子、屏幕或其他封闭/安全装置。简而言之，提前解决这些因素比以后提起诉讼更为明智。特别是，如果后来声称其设计存在某些缺陷。需要明确的是，安全使用的责任在于消费者，但在我们当前的诉讼社会中，提前解决这些问题比事后回应要好得多。
制造商应首先决定所售出的每个戒指是他们的“产品”，还是只是按照客户的订单和规格制造的“零件”或一组零件。虽然这两个案例可能会导致类似的结果，但两个案例之间的差异在法律上可能是“可区分的”。不过，您很可能会遇到向您征求建议的客户。在这一天到来之前与一位优秀的律师交谈是明智的。假设产品责任保险对普通制造商来说不是问题（太贵），那么每个售出的戒指（应该）包括适当的警告和免责声明。理想情况下，这些应以印刷形式和实物形式提供。物理形式的范围可以从清晰设计的标签到产品本身的激光/等离子雕刻。警告语言因地区而异，但应指明产品的用途（木材、木炭等；或不是），并包括描述安全操作的声明——例如“切勿让火无人看管”、“戒指可能很热” ”和/或取自国家公园管理局、林业局和国家防火 (NFPA) 等来源和类似来源或协会的语言。 （例如，想想 Smokey Bear 会说什么）。一旦解决了监管和法律问题，您就可以将注意力转向设计和生产。

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定义。

从基础开始，让我们定义一个火环。火圈是明火的围堵装置——无论性质如何。许多具有纯粹的美学功能，作为更大设计的重点或元素
如（丙烷/天然气）装置旨在帮助定义后院娱乐空间。火环还提供一些间接照明、烟雾管理和热反射的措施，具体取决于设计。出于本文的目的，我们认为术语“火环”包括适合休闲消防服务的所有形式的设备，只要它们不可燃、顶部敞开、高度至少为 6 英寸且纵横比为环形或多边形创建有效的火灾和火灾副产品的遏制，或者将热元素与二次遏制设计（例如石头、砖块或附近环境中的其他材料）分开。火环不是燃烧桶、桶、桶、桶或其他更垂直发展的形状。环的形状由自行决定，但可以描述为“成形”或“分段”。成型的形状被弯曲或滚动以形成它们的形状。分段环由任意排列的任意数量的平面组成；无论是永久固定还是能够拆卸。在任何一种情况下，零件或零件的数量都无关紧要，并受材料成本、运输限制、美学和预期最终用途的影响。考虑到这些术语，让我们回顾一些基础知识：设计、材料选择、厚度、生产方法、问题和运输/安装。

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设计。

产品设计的范围从概念到重新设计，因为在开发的原型设计阶段会注意到成功和失败。真正的产品是什么并不重要——步骤是一样的。有些只是由于其复杂性而需要更多思考，但无论产品是什么，采用迭代方法都很重要。无论您从哪里开始，都应该有另一个版本待定，这取决于您在随后的过程中学到的知识。您最终必须确定要构建和销售的设计。即便如此，来自客户的反馈可以而且应该推动下一次运行或模型的发展。不这样做可能会导致过时；可能是市场失灵。想想你的汽车或手机在 10 年前是什么样子，你就明白了。很少有产品是真正“永恒的”。愿你有幸发明下一个。即使是永恒的设计也不总是成功。无论如何，不​​适合原始设计师。在军队中，您会了解到“没有任何计划能够在最初与敌人接触时保持不变”，因此企业主面临的资源争夺战也是如此。如果没有一些成长的痛苦，就不可能从餐巾纸或 CAD 程序中获得所有设计。尝试将自己从“您的”设计中移除，并保持对输入、建议和市场反馈的开放态度。你的“完美”设计可能只对你来说“完美”。市场是除你之外的所有人——所以让最好的设计获胜，无论它是否正是你的发明。

请记住，这是一个由各种情况和背景的人组成的大市场。卖给周末露营者的东西将不同于屠夫、面包师或烛台制造商想要的东西。例如，永久性环与可压缩分段设计。然而，在任何设计中，选择灵活和宽容的设计都是明智的。灵活的设计允许客户预先选择一些范围，并能够在未来添加和/或更换零件。例如，允许用户根据火的大小和高度堆叠或伸缩环的设计就是一个例子；滑动通风口、用于通风和除灰的“门”、防雨罩、烹饪表面、烤架和硬件也是如此。
容错设计允许根据偏好或可用性选择一系列材料。公差设计在形状和材料厚度（在合理范围内）方面也是“可扩展的”。容差设计还将对齐、边缘特性、光洁度和变形等问题作为切割、机加工或组装过程的副产品考虑在内。这包括由切割弧产生的拔模角、焊接斜面、紧固件和构造、修复或完成/涂漆设计所需的间隙。无论采用何种设计，直径越小，环与火和热煤接触的可能性就越大。例外是丙烷/NG（天然气）装置，其中火焰不应接触主安全壳。然而，所有的环都倾向于收集辐射热，并且当火被管理不当时会出现红色/黄色热点。考虑一下您的设计将如何受到切割操作、焊接、客户疏忽或火灾本身造成的热应力的影响。低碳钢在加热时会移动很多。在一个直径为 48 英寸的环的周长上，所有这些都加起来并且必须去某个地方。热量会使薄弱的接头变形和受力，使面板部分翘曲，并束缚任何没有足够间隙设计的运动部件。

无论您的产品或设计如何，都应该在开发工具、制造夹具和切割大批量生产之前进行彻底的测试。设计和评估过程需要考虑更多——更多。从市场研究到破坏性测试。至少，您的设计和流程应该由与其开发无关的人员进行审查。如果可能，此步骤应包括您操作生产方面的人员，受指示寻找设计弱点、潜在错误，并检查制造产品所需的所有工具和流程的实际许可。应咨询另一个人（或公司）以独立评估产品的预期用途和滥用。只要有可能，这种评估应该在它打算使用的环境中进行。应该付出一些努力来预测或观察时间和老化将产生的影响。材料是否符合预期；一旦热量、污垢和灰烬进入方程式等，是否有任何运动部件容易卡住或卡住。

如果资金允许，还可以尝试光洁度和外观。颜色和表面光洁度等因素通常会推动市场接受/抵制。一旦您的成本合理地知道，然后尝试确定市场将接受的价格。交换会、跳蚤市场和贸易展是获得反馈的好地方。你甚至可以用“折扣”优惠券来激励这项研究，并赠送一些物品，例如可能比对参加者的随意调查产生更准确的信息。目标是在合理的费用和努力水平下尽可能多地评估您的产品。包括外观和你的价位的关系。

有时被称为“合身”，同样的基本黑色设计可能只需要一个基本的价格。用烫金或铜老化配方处理相同的设计可能会将相同的设计变成更有价值的东西。复杂且执行良好的剪裁调用人们可以识别的场景是成本、努力和美学的另一个例子，它们可能会或可能不会吸引足够广泛的客户群，以至于值得作为库存生产以期找到客户。一般来说，在给定的模式（可以）和/或“应该”在给定的火环中重复的大小、细节和频率方面，“少即是多”。细节太多，很难整体区分。切口也可能会降低材料的强度，这可能会影响环弯曲的均匀性。未受干扰材料的边界应沿环或弯曲件的长轴保留：顶部、底部和末端。根据弯曲半径，一英寸到一英寸半通常就足够了。设计可能必须偏向环的上边缘，以避免被泥土遮挡，
灰烬和土壤。切口还会影响诸如烟气迁移、煤炭遏制和切口投射的阴影等质量。后者是需要在展会和销售文献中关注和“展示”或展示的东西。我们的经验是，与长串的风景或其他细节相比，一些位置合理且执行力强的不同形状更容易被接受。一只孤独的麋鹿应该看起来很孤独，并且会唤起杂乱无章的鹿群所没有的情绪——无论鹿角有多大。鹿、鸟、团队标志等也是如此。自定义字体、标语和个性化名称可能是例外。字体需要以易于阅读的字体进行区分，并根据需要正确标点符号。富有表现力的字体中的细线字母难以阅读，并且不会像 Times Roman 和类似的常见样式这样的字体那样投射阴影。如果蓬勃发展的脚本对客户来说是必不可少的，那么可以考虑用不锈钢等反光材料固定或焊接在它后面约四分之一英寸处（环内部）进行阴影照明。理想情况下，火光将在白天和火光下照亮刻字。或者，可以使用紧密编织的冲压或金属网筛网，它具有减少火花和余烬被吹出环的额外好处。
设计的可能性是无穷无尽的，但最终的问题仍然是这种差异是否值得作为常规生产问题或作为一种选择来追求。无论如何，可以使用两个或多个选项之间的比较来增强基本模型的价值或更多排他选项的价值。如果只是为了增加产品线的深度，爱国、团队和品牌标志都是值得评估/提供的选项。一些客户在看到之前就知道他们想要什么。绝大多数人需要有多种选择——努力提供它，或者切割样品供所有人查看，以及打印质量非常好的小册子或可以随身携带的页面。

从那里你的产品需要做广告和分发。在当今的媒体环境中，您可以直接营销您的产品。开标是一个设计良好、易于使用的交互式网站，无论观众选择什么，它都可以在任何东西上运行并快速加载。如果您有能力自己做这件事，那很好——但它需要看起来很专业，而不是崩溃。如果您不擅长技术，那么有很多这样的服务可供选择，而且价格便宜。
您使用网络和社交媒体的目标是吸引点击量并将其转化为销售量。 E-bay、Craig's List、Etsy 等网站都是您产品的可能场所；当地的机会也是如此，例如展览会、季节性展览和出售展位空间的活动。它可以是有利可图的，但营销工作与制作它一样多的工作和努力。一项努力应支持另一项努力并保持同步。没有人相信过时或根本不会改变的页面。这需要您一天中的时间，并且电子查询要求响应至少与电话或短信一样快。如果您没有那种时间（我没有），您可以聘请营销和分销公司为您处理这部分业务。它可以是有效的，但它是有代价的。根据所涉及的数量，从售价的 5% 到 40% 不等。但是，世界上设计最好的产品实际上毫无用处，除非人们开始了解它并希望它足够糟糕，否则他们将花钱/塑料袋拿到它。
试图在不至少关注现代媒体趋势的情况下进行竞争并不是成功或未来的策略。但选择权在你。除了购买多余的库存和大量无法出售的商品之外，什么都不做的人也在做一项强大的业务。真诚地，我会免除您加入那些不幸失败的努力的成本和痛苦。彻底评估您的设计和意图。每一分努力和花费都是值得的。

最后，您的设计需要既适合市场又适合您的生产成本；合理的利润、管理费用、税收和所有考虑的费用。太多的制造商因为未能了解他们认为要参与竞争的业务的更大方面而失败。比该领域的其他产品和制造商便宜本身并不是一种有效的商业战略。很多时候，客户不了解公平的现行劳动费率，例如，即使是在给定的领域。因此，与当地替代品相比，比当地替代品便宜一些甚至便宜很多是一种长期无效的策略——即使它得到了有效的宣传。考虑碰撞修复的全国广告。总有更便宜的地方可以修理您的汽车。几乎任何地方都可以找到小商店，就像很多人用螺栓固定在卡车上的便携式焊机，侧面有磁性“焊接”标志。他们的公司是由那辆卡车或车身修理厂里的东西来定义的，仅此而已。这对他们来说很好。投放有效广告的成功公司往往不会强调维修成本，而是所提供的服务和所做工作的完整性。他们鼓励与不频繁和折扣服务建立持久和可靠的关系。

更通俗地说，火环在某种程度上是可自由支配的购买。在此类购买中，质量和美学很重要，而且设计的独特性通常会加强客户的身份，因为它与在线和大型零售商的库存有区别。价格通常不是他们购买的驱动因素。在这方面，我们的行业有一个小众市场，因为相对较小的编程更改确实以适度的更改和生产成本呈现非常个性化的结果。人们想知道他们以合理的价格购买了好的产品。他们可以感到自信和信任的人做得很好——特别是如果他们的意见表面上被纳入了。一般来说，最好在您的运营和成本结构中以公平的价格为您的产品定价 - 有时称为“收入模型”。如果您想在客户服务、与客户相处的个人时间，甚至以折扣价提供升级方面为产品增加价值——这些都是更好的策略，而不是简单地仅以价格为基础进行竞争。学会更有效地利用废料、简化生产流程并最大程度地减少返工是对您未来和长期成功的投资。与该地区的其他制造商相比并不便宜。

智能产品设计必须考虑所有这些因素——包括您选择用于生产产品的技术。在您渴望制作的设计中保持现实是很重要的。试图在具有可以切割结构铁和火环的等离子台的设计中产生类似激光的精度可能是不现实的。仔细考虑你的图案的细节。指定的最小半径与您的桌子实际切割的半径相反。查看火焰切割边缘的轮廓；它的拔模角度、直线度和“线性度”。您的表/程序是否干净地切割对角线或作为一系列阶梯边缘？然后将这些与您的设计进行比较。在详细描述树木天际线的设计中，阶梯边缘对角线可能是完全可以接受的。可能没有那么多刻字。是否值得升级甚至只是维护您的桌子与花费时间和金钱在切割后清理上是个人意见的问题。如果把钱花在桌面上，很有可能会产生长期收益；
后整理操作是沉没成本。在这两种情况下，这里唯一要做的就是选择一种你知道你的机器和人们可以以最低成本实际生产的设计。然后寻找改善流程结果和效率的方法，以进一步降低成本和浪费。与往常一样，尽量不要谈论您必须努力按照所需规范进行生产的工作。这种工作很诱人，但最好的结果是利润低于预期；最糟糕的是，一个失望的客户可能会在您不知情的情况下为您做广告。在前世，我是一名牧场主。每天早上，我们一群人会聚在一起吃早餐并讨论业务。这就是我们在需要时“联网”并互相帮助的方式。当我们中的一个人有一个“故事”要讲述给定的维修或供应商时——你可以打赌其他人听了。从中获取您想要的东西，但重点是您的工作被讨论的次数远远超过您的想象：好与坏。尤其是当涉及一个人可以自己制作的产品或维修时，如果他们愿意的话——但只是太忙于（小腿）而没有时间去做。火环就是这样。
所以要现实地看待你“在镜头中”的能力（今天）；不是它“本来”的方式，也不是您的机器和人员“应该”能够做什么。一个现实的基线比你或他们“可以”甚至“通常”做什么的记忆更重要。人们来找你是因为你的声誉或可用性。他们带来了他们的期望；无论是在寻找个性化产品还是在绝望中。您的工作是管理所有三个方面：声誉、期望和盈利能力。在合理范围内，通常只有一两个是可能的。

如果您的生产结果滞后，您有两种选择。你可以改变人，也可以改变人。这也适用于技术。任何一种方法都需要时间和金钱。我的经验是，您必须同时做到：改变人员并与技术保持同步。您必须首先对自己非常诚实，但要确定您的商店、设备和您的期望是否切合实际并且非常适合该任务。太多的所有者期望一台使用了 20 年的旧机器可以生产出相同的结果，但它可以生产新机器。例如在焊工中：如果您没有监控基本情况，例如衬垫的状况、更换焊嘴的频率、引弧前的准备工作、飞溅喷雾的使用和耗材，您就会错过有关人员和成本的宝贵数据。即使是像带锯条这样简单的东西也需要改变频率，这对锯子的状况和/或使用它的人的勤奋程度来说都是很重要的。您的员工是否设置了锯子并放下刀片，以便他们可以在切割（或撕裂刀片的牙齿）时查看短信？或者他们是否小心地放下锯子并监控切割的漂移、停顿、热量以及它切割的芯片的尺寸/颜色？

无论如何，请仔细选择您的工作、技术和人员。如果您的业务是工业楼梯和重铁 - 火环可能不适合您的商店。另外，考虑一下如果切割台坏了，你的程序员生病了，或者一个关键人物在工作中途离开，你的备用计划将是什么……所有这些都只在你最不需要的时候发生。您需要有一个计划和方法，以便在需要满足最后期限时采用另一种方法或技术。营销和销售人员在销售旺季前大约 6 个月的时间紧迫。错过发货日期，您可能会毁掉一笔交易。如果像火环这样的副产品的生产与您的繁忙季节（例如 PNW 的夏季）发生冲突，您在休赛期增加收入和稳定现金流的尝试可能与您的目标不一致。评估您是否可以/应该为已经很忙的商店施加压力，为材料提供资金并进行生产
淡季期间的费用。这样做是可以的，但要冒着风险，即您对几个月或一年后会销售的产品的看法仍然具有相关性和市场价值。

在理想情况下，您的设备可以完美运行，并从其他项目中切割出完美的设计……您可以在其他更有利可图的项目之间或在轮班中作为补充工作运行。理想情况下，您的工作人员每次都可以完美地制造零件，并且您对戒指的需求量比您有时间的本地市场还多，甚至无需为它们做商业广告。如果这描述了您运营中的任何产品，那么您将比您意识到的更有福，我为您感到高兴。对于我们其他人来说，这比人们意识到和/或愿意支付的要多得多。

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材料选择。

在材料选择方面，我们明显偏爱热轧低碳钢。您可以用其他钢（包括不锈钢）制造戒指，但这样做需要权衡。例如，成型、弯曲或焊接材料的能力因配方和表面处理而异。铜和黄铜等有色金属材料制成的戒指很有吸引力，但不建议将它们用于明火，因为它们不能很好地耐受极端高温和天气。尽管铜和黄铜为钢主环提供了极好的装饰——尤其是在设计合理的丙烷/天然气装置中——但它不是主密封的好选择。切勿使用镀锌钢和铝。戒指也可以由重新利用的材料制成，并取得了一些成功。
在热轧低碳钢类别中，您有两种基本选择：板材或板材。

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钢板。

该板通常每平方英尺或每磅比成型形状更便宜，并且以空间和重量为代价提供更大的设计灵活性。然而，潜在的节省需要卡车运输和在合理时间内卸载卡车的能力。如果您有叉车或一些从路边吊起和提升负载的方法：太好了。如果不是，那么您所订购的产品每 1/4 英寸每平方英尺大约 10.2 #。在 1/4 英寸的 4 x 8 部分中，您需要清除、降低和移动 300# 而不刮伤或弯曲它。它可以由几个强壮的人、一台挖掘机或一个起重架来完成。想想农场或牧场的经典“H”或方形入口，你就会明白。在过去“离岸价”的日子里是指房屋的入口和用于将货物从一辆货车转移到另一辆货车的升降架；卡车到卡车……现在我们有了液压系统和装卸平台——这意味着你（可能）只需要一个液压地板千斤顶、木头或管道滚轮、小车轮等就可以移动一个大尺寸的板……但是然后呢？外部存储会影响表面的光泽。内部存储在为其构建的机架中很好。但这一切都是以时间、劳动力和更大的受伤风险为代价的。人们被垂直存放的盘子砸死。水平存储更安全，但您的货架需要能够处理巨大的负载并具有内置的安全余量。独立式货架很好，但带轮子的货架有风险。无论您使用何种系统，当您卸载、移动、存储、切割和清理板材库存时，无论您的设计、零件或产品是否有效，您都将在此过程中投入资金。不要误会——我们每周买一盘。但是我们有两台叉车和一个切割台，足够大，可以铺出 4 x 8 的纸张，并留出空间。如果您使用的是 2 x 2 或 4 x 4 切割台，您可能会发现有一些板材的替代品，最终整体加工成本更低。

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平仓。

如果您的设计可以由宽度为 12 英寸或更小的部分或运行制成，那么扁平库存可能值得考虑。扁平材的厚度为 1/16 或 1/8，宽度为 1/4 或半英寸。 （HR）中的表面处理是蓝色或灰色的氧化皮，尽管我们最近有大量橙色（？）。表面上可能会出现滚动痕迹、一些裂纹和条纹，但通常是微不足道的。表面的 RMS 会随着从光滑到坚硬的喷砂外观而变化。扁平材在其宽度上相当均匀，但可能会带有钩子或在其长度上弯曲。运输中的弯曲和损坏并不少见。如果需要精确，要求将订单捆扎、拉伸包裹和/或包裹在一段木头（板条）或托盘上。 The ends are typically sheared and distorted but the edges are typically a uniform rounded or blunt shape. Widths can vary lot to lot and supplier to supplier – but not typically enough to matter in a fire ring.
The advantages of flat steel are many. First, the typical length shipped is 20’ so only one seam is needed in an average fire ring. It moves easily on a section of rollers and cuts easily in a band, disc, or metal saw. Density across the section varies a little as sections get thicker but not enough to matter in a fire ring. It is also easy to bevel and cut diagonals and compound miters through. All of which can be done with a hand-held plasma cutter or on the plasma table too. Cutting (anything) on the plasma table comes with the risk of heat stress, slag or dross, variations in the edge profile as the flame wavers, and changes in the patina in the heat affected zone and where water and slag rebound on the underside of the material. In almost every case, flat stock is cheaper and easier to process than sheet materials regardless of the price difference compared to the plate. The exception is wherever a uniform patina is required. Finishing flat stock to match the unblemished appearance of mill scale plate is an art in itself and may be addressed in a separate article. It is work to uniformly remove the mill scale from any material and variations in stock surfaces can compound this effort. If your design requires homogeneity then test this before you order large quantities.

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Repurposed Materials.

Fire rings may also be constructed from repurposed materials. For example, large truck tire rims, sections of old cylindrical or oval steel tanks, cable, chain, car parts and virtually anything else you have the imagination to fabricate into a ring or geometric shape fit for the purpose. The costs of repurposed materials range from free to scrap value plus transportation. The risk of using repurposed materials centers on at least two aspects. 1) the hazard of whatever the item used to contain as a pollutant or hazmat, and 2) the risk of fire or explosion on cutting the material up for repurposing. Tanks are obvious hazards but every year people are injured by welding and cutting on shapes that explode
or catch fire in the process. The only way to mitigate this risk is to clean and empty the item until the risk of contamination, pollution, and personal injury are eliminated. Taking shortcuts in this process is not a strategy for success. Repurposing material can be very rewarding and produce some very attractive products. In general, these are one-off pieces however and therefore defacto intended for regional sales or sale through the web (Etsy, E-bay, etc). Profit margins are more difficult to estimate in such products and typically require more labor to produce than similar purpose products made from the virgin or remnant material. Shipping costs may likewise be inflated by the reinforcement that (some) artistic interpretations require due to their fragility, finish, or other characteristics.

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Thickness.

Thickness is directly related to cost and the longevity of the product. There are ring-like products marketed by some very well known brands that are essentially made from sheet metal. I encourage you to study these products carefully though I suggest that you will not likely be able to compete with them and probably should not try to do so. Rings made from sheet metal should be avoided unless the attraction of portability and compact design are your marketing vector. Even in such a case 18 ga is about as light as we would suggest considering. Our experience is that lightweight rings do not last very long in any environment and are unsuitable for permanent installations. Lightweight rings may also have sharp edges and are easily bent or damaged in use/transport. There is a market niche for such products but suspect you will find more interest in a more robust “quality” ring that permits individual customization in terms of weight, height, and design/cutouts, etc..
1/8th in the material is the thinnest we prefer to use and have made rings as thick as ½ inch plate. Shapes made from 3/8” hot rolled mild steel are not uncommon in permanent installations. Three-sixteenths (3/16) to quarter inch (1/4) material strikes the optimum combination of weight, strength, ductility, longevity, and production-ability in my opinion. Quarter inch material averages 10.2# to the sq/ft and are the most tolerant and compatible with (our) production practices. Obviously, the thicker and wider the material the more difficult it will be to form, handle, weld, and ship/deliver.
In designing your product remember that thickness does not describe everything about strength, utility, and/or the processes required to fabricate the design. For example, ¼” mild steel can be rolled efficiently. The same diameter in stainless will require more effort and be harder on your equipment.

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Production ability.

By far the single most important factor in launching a successful fire ring product line centers on the efficiency and reliability of the manufacturing process. Small details often make the difference between profit and loss with labor (time on task) being the most expensive variable of all. Care should be taken to evaluate each design and the special requests of the client before any metal is cut. Wherever there are doubt patterns should be made from scrap or plywood. Take care to make your patterns from a
dimensionally stable material of similar thickness to your design. Paper and cardboard patterns are useful approximations of a design and fine for prototyping and fit-up where some weld clearance is required anyway. The standard in pattern material though is medium density fiberboard (MDF) and only surpassed by high-density fiberboard (HDF) – both of which are essentially uniform stacks of paper glued and pressed together. MDF cuts and routers well and is generally fairly flat across the sheet. It is only mildly moisture resistant though so patterns should be painted and sealed if they are expected to survive years in an ambient air environment. The material is not cheap but cheaper than plywood suitable for patterns (many plies; no voids; sanded, etc.). There are no voids in MDF and if you keep blades sharp little more than a fine paper but will have to be removed with a brush of a glove or sanding block.
For shapes that must be deformed (like a fire ring) then a good pattern material is a plastic shower liner, Formica, and sheet metal. Shower liner (FRP or GRP sheets sold at lumber centers) comes to both smooth and pebbled finish and in at least two thicknesses. If your shape is large, consider the glass reinforced variety but understand that you will have to deal with the fiberglass dust as you cut and work with it (no pun). Sheet metal must be thin enough to deform uniformly but not so thin as to crease easily or be difficult to trace. 18 ga is a good compromise overall.
Thermoform plastics may be bent with heat; thermoset panels less so. An electric heat gun of 12-1800 Watts is perfect. A propane torch can be used if a diffuser tip is installed – but the hot air heat guns are far less likely to damage the material than an open flame is. If your design/pattern requires tapping, bending or breaking then consider the thermoform species of plastics like acrylic (plexiglass) or polyethylene (HDPE and MDPE) for your pattern. It is not cheap or even cheaper than MDF but more versatile and stable than HDF, MDF, or plywood but the ability to see through an acrylic pattern can be priceless. If the economy is essential then look for a plastic supplier that also does custom cutting and some fabrication. Such places always have drop or rem sections that can be purchased cheaper than virgin material. Both HDPE and Acrylic may be bent, drilled, tapped, and cut or shaped with a router but blade speed and direction of travel is important. Especially with products like Lucite, Lexan, Plexiglass, styrene, and similar. Use a dull blade or bit, the wrong speed, direction or technique and you will be left with a melted or chipped edge to repair or discard. Painting acrylic can be a challenge (persistent fish eyes), but it can be easily glued with the proper solvent (MEK, etc). Where strength is required to avoid simple flush fitting joints –especially when making tee sections and 90-degree corners. You will get a stronger joint if you 1) abrade the joint surface to 100 grit or so, and 2) rabbet a shallow slot or groove into the plate being joined. Likewise, consider a stepped joint at corners whenever possible. 45-degree bevels are more difficult to get right. Stepped joints are more tolerant of subtle variation in your prep and/or the material. Either approach may be easily cut with a table saw or with a router. HDPE welds quite well as do many other thermoform plastics like PVC and ABS. This attribute makes rapid prototyping strong, simple and cost-effective. Plastic welding is a skill however and about on par with the skill TIG welding requires. Good equipment is worth its cost. Avoid the tempting discount hot air guns. Trust me on that one…
For one-off or limited use patterns Silicone caulking, construction adhesives, or a hot glue gun can be useful in making fixtures and the prototyping process. Tube-based caulking should be of the fast setting type. For ultimate strength consider the moisture cured urethane adhesives on the market. 3M’s 5200 Fast Cure is particularly effective. Though more expensive than even the best 100% silicone caulking out there, 3M 5200 is both an adhesive as well as a gap-filling caulking. Cure times can be accelerated by spraying a fine mist of water on the joint – making overnight shop-to-service jigs possible. Whatever material used, be sure to consider the space that weld fillets need and either add to exterior dimensions or remove from internal clearances accordingly.
Designs that require substantial post-production (welding) clean up and grinding cost more to produce than those that do not. While some ingenious designs may be assembled via interlocking tabs, with fasteners, etc. Choice of the welding process is another consideration. Errors in fit up and heat distortion can cost more to correct than the steel is worth. Customers can also be very critical of heat affected zones, gobby looking welds, and distortion - but these are nevertheless the very details that customers look for and expect in a quality product. Wire feed welders have become the standard but by no means the silver bullet of processes. Where a classic look or certain aesthetic is required I suggest you consider alternatives like rivets and custom fasteners on the finish side of the ring – maybe backed up by discrete welds on the less visible surfaces and concealed edges.
Production ability can be improved by the intelligent use of fixtures. A fixture is a device that aides the assembly and fabrication process. Whether as simple as a saw stop set for repeated cuts or an elaborate design that holds any number of parts for welding. What matters is that the fixture is accurate and robust. They need to be strong and designed to last however many cycles you expect or hope to run. Season after season – without use and abuse being able to introduce enough error or distortion as to affect the reliability of the process it supports. This includes cutting table fixtures which are useful for material that is prone to distortion. All steel has a grain and internal stresses. Heat – as from the plasma arc – tends to exaggerate these stresses which can twist and curl thin sections as you progressively use the sheet – especially in thinner material and in thin cross sections between cut shapes. Fixtures and clamps can minimize the chance that a section will distort enough to catch on your cutting head or beam – which in turn may drag or turn the part mid-program. Not good; and expensive. It is better to cut off the remnants of previous shapes and concentrate your mass than to have the remains of a previous job ruin your resent part. Using strategically placed magnets to help hold the sheet down can be helpful as of course can clamps or scraps of a heavy plate positioned in areas the cutting head will not approach. If your table uses water/bladder system then, of course, these aides can be bagged, painted, or otherwise protected to assure their longevity and cleanliness.
No matter how your material is cut, bent or formed your jig or fixture must support the weight of the material as well as whatever force is required to shape or bring edges into alignment. Add the weight of the person working on the part leaning or standing on the assembly – if just to steady a weld procedure – hammer blows, transport, storage, and forklift abuse and forces compound quickly. Fixtures may be free-standing or mounted to a table… preferably an all steel welding table of sufficient weight and thickness to remain flat and allow you to exert force and leverage on the part however needed.
Rolling machines sometimes put a slight twist in the steel band being bent. This can be removed in the fit up the process but makes the process of hitting a precise diameter cleanly a much more challenging process. Rings are essentially giant springs anyway so some thought should be put into how you intend to join the ends of the material safely and according to the aesthetic characteristics of the design.
Lap joints are the strongest and lend themselves to several methods of fastening. Lap joints also make use of the “flats” or tails left on either end of the bending process typical to roller bending machines. Rather than simply cutting the flats off in order to approximate a perfect circle, consider using them to your aesthetic advantage.
If a perfect circle is required – for example where the ring is being used as a border on a sand or gravel propane/NG permanent installation – then the tails must be cut and married as seamlessly as possible. This joint in particular is an example of where a jig or fixture really proves its worth. Another simple fixture is a circle routed into a sheet of plywood or MDF the diameter of the ring intended. A nylon ratchet strap works well to pull the ring together so long as the ratchet is not near the seam. At a minimum, you should use a simple section of a ring of the same diameter as a clamping fixture to assure that the joint is made on the same radius or curve as the balance of the ring. This will require a section from a quarter to a third of the diameter intended. Once clamped the ring can be tacked or stitched enough to hold its shape before the fixture is swapped to the other side of the ring and reattached so that the other side of the ring can be similarly tacked and then welded. Failing to control the accuracy of the curve will result in a ring that looks quite amateurish and unsightly. Fit and finish the matter. If you can cut or shear a clean edge you may be able to weld only one side of the ring and let the edges neatly butt on the finish side. This seam can be left plain, painted, or accented with a contrasting material – like a strip of brass, copper or stainless. One effect we like is a rim or trim ring around the upper edge of the ring. This can be anything from a rolled edge or slit pipe bent to match the circle or shape – to a simple piece of ¼ by flat bar welded around the upper edge.
Carrying this idea further, additional strips or shapes can be added around the perimeter to mimic the cardinal and intercardinal points of the compass (N, NE, E, SE… etc). The fleur delis and diamond are common patterns used on a compass. Using this approach to camouflage seams and other details is both smart and good business. Frequently the drop or cut-outs from whatever design was cut into the ring – or from other projects - make perfect camouflage as accents. Especially if you keep your “lead in” angles shallow and distance short; or repair these tracks … Using external accents lends depth to the design. Many people associate the complexity and depth of a design with quality – so using your cutout circles, diamonds, trees, elk, logos… anything really – is like turning lemons into lemonade. So keep an eye on how your production challenges can be turned into an opportunity to embellish or otherwise upsell the product to everyone’s benefit. This approach is especially valuable when the original patina and finish of the factory must be maintained. Keeping a perfect mill scale finish is harder to do than it sounds like everything from splatter to normal oxidation makes keeping the mill finish intact a decreasing probability over time.
Another approach to joining the bent section is to cut a long diagonal or stepped diagonal “scarf” joint in the ring. This is a more challenging joint than a simple butt joint but can be worth the effort for the sake of its appearance and manner in which it preserves the shape of the ring better than a butt seam does. For rings of thinner material, you may need a backing plate to bridge the seam and add some support several inches either side of the weld. If your design permits an exposed welded seam, and/or the finish that post welding grinding and sanding leave you with;伟大的。 For thicker material, you should leave a space between the plate ends and/or bevel the plates being welded to assure penetration. A copper strip is a good backing material to push against while welding any gap or hole – if you have it. I have experimented with using aluminum sprayed with non-stick welding spray instead and it works pretty well too. The objective of either is to temporarily support the weld pool until it freezes in order to minimize the amount of material and carbon deposited on the opposite side of the seam.
Accept that any welding process will affect the patina of the metal though – backed or not. Stainless is especially prone to distortion and discoloration when overheated though it can usually be restored with some effort. Special consideration, care, and equipment should be considered when welding stainless. For wire feed machines, using a bit higher shielding gas pressure/volume and limiting the effect of ambient drafts in the welding space goes a long way. The cleanliness of the material is critical as well – especially if TIG is your process of choice. Be sure to clean your material and your rod carefully. Acetone works well for us. Brush or grind your starts and stops to keep inclusions to a minimum. If TIG is your only recourse then I encourage you to learn about the various aftermarket gas lens and cups being sold by Furick and other vendors. Especially in stainless production, these additions can really up to your game and the appearance of your product in the process.
Once you know what the effects of heat, stress, and welding are, then fit up and welding will be your next biggest challenge. Mill scale must be removed to get an effective bond but comes at the expense of the final finish. I encourage you to post-finish parts rather than try to sell them in the “raw” mill finish post production. The exception is in “kit” form where the customer will paint the product themselves. If you are selling to an installer or contractor then a decent primer may be all that is required to preserve the ring without the expense of finish painting that the contractor needs to drill through, tack in place or otherwise alter in the installation process. Clearly “something” should be applied to the surface however as steel being steel will age as it is left out on the job site, scratched, abused or just stored over time. Powder coating, in this case, is not worth the effort or expense. A better alternative is cold bluing which is essentially a solvent-dye formulated to bond with the base material (think layout dye). It comes in brown, blue and black; the browning solution is especially easy and attractive. More complex colors and dyes exist that mimic copper, bronze, and other patinas. All can be applied by spray, dipping, a roller or a brush/rag. Spraying yields the best results as dyes will leave streaks if brushed or wiped on with a rag. If you can find a roller that will stand up to the solvent then a good foam or short nap roller may work. If you do spray keep in mind that the volatized solvent dye is not something you want to be breathing. Your parts will look “finished” at a minimum of effort though. Dye tends to stain anything it comes in contact with – including people. So a dedicated area and some containment/PPE is appropriate. Disposable plastic or cardboard is a good idea. OSB and plywood are good flooring choices but the sheet or corrugated metal is, of course, safer for the walls. The material is highly flammable (of course) so some fire preparedness is wise. Paint is cheaper than dye on the surface but requires more time to dry than a dye. Powder coating is probably a wasted effort in the case of a fire ring. Any paint will burn off eventually though the high heat versions used on engines and BBQ’s hold up a bit longer. This is an area to consider carefully as the cost of fit and finish is substantial and affects marketability – yet in the end, it is a perishable quality as the ring gets used.
One alternative is to use a different type of steel (different chemical composition) that ages somewhat uniformly – like Corten (sometimes Korten) or even stainless if your market will support it. In the case of stainless:grade has everything to do with durability. Many “stainless” products sold on BBQ’s and similar consumer goods rust over time. Opening bid is type 308 and there is a version formulated for high heat and sulfur exposure (in the 400’s) but it comes at a price that likely will be appreciated by few. All these materials have differing levels of productionability and welding requirements and respond to bending, punching, bending, etc. differently than 1018 mild steel.
Another approach worth considering is pre-aging the material yourself. This typically requires stripping the mill finish and using a range of oxidizers to essentially oxidize or rust the material. You can do the stripping mechanically or by electrolysis. The advantage of electrolysis is the ability to get places that grinders and wire wheels cannot. Plus you can do batches of rings at a time. But this is a topic in and of itself as everything from choice of solution to electrode placement affects efficiency. The striped appearance is a lot like sand or bead blasted steel – which is another alternative. There are lots of blasting places that can be contracted with if it just is not in your means. No matter how you strip the steel, post finished results of an oxidized surface is predictable and very typically rust colored. The steel can be colored instead though:from bronze to copper, etc - but not inexpensively. In the end, the product looks about as it might some years on exposed to the elements but heat and soot will nevertheless foil your best efforts eventually. The exception being primary containment rings/shapes installed in propane/NG installations that never really get hot.
Final packaging needs to be considered as well. This can cost more than the steel. Stacking finished rings someplace in the shop for later distribution will only result in dusty rings later. Shrink or stretch wrap is a cost effective approach. Boxing may be required if you use a distributor. Study the methods used by importers from ROC. They have brought this expense and effort to a new level of efficiency and “value engineering”. Local markets may permit a minimum of packaging but every ounce of protection you provide up front will pay off in loss reduction later. Remember that your packaging is also a reflection of your company and influences the perception of quality in the consumer. Since the advent of digital printing, this expense has been reduced but is still not insignificant. Warnings and product limitations of (liability) should always be shipped with each ring and permanently affixed or otherwise engraved/stamped into the product. Consult an attorney hen composing this message and keep the fonts legible and large enough to be distinguishable (12 -14 minimum). They may be placed on the inside of the ring for aesthetic purposes. A bright colored dot or shaped label may/should be placed adjacent to the notice to call attention to the message. This may double as a “QC” or inspection record. An ounce of prevention is worth many billable hours later…

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Summary.

Fire rings are a good project to experiment with your ability to launch a product line – at least regionally. Like any product or venture, the challenge is in managing the finer details and processes required from inception to delivery. Fire rings may provide a worthwhile revenue stream and potential installation revenue. A methodical and realistic approach is required to efficiently produce a marketable product. Seasonal cycles and demand must be considered against your core business trends. The availability of slack production time, drop or rem from other stable product lines, and space to produce and store finished product some months in advance of the selling season – all contribute to profitability and efficiency.

Vincent Cantwell,
Vincent Cantwell is a fabricator working at Mac Welding in McMinnville. Responsibilities include welder, machinist, fabricator, layout, and product development.