Custom Metal Fabrication – Preparation Stage

Written by admin, 27 March 2021

This custom metal fabrication project involved very sophisticated steel fabrication and aluminum fabrication. JW Portable Welding & Repair, London, Ontario, 2020

The custom metal fabricator in its custom metal fabrication project chooses custom metals for the project due to their physical and chemical properties and other mechanical components such as toggle clamp. From a custom metal fabricator’s point of view, the project require

  • more advanced welding machines,
  • custom metal welding consumables that include abrasives and welding rods or wires and,
  • perhaps more advanced welding skills supported by theoretical knowledge.

Additionally, these projects could involve heat treatment and/or machining of parts made from different alloys. The custom metal fabrication projects often become very complicated and complex. Wrong decisions made at beginning of the project can have significant consequences at the end of the project.

Custom metal fabrication of mechanical structures

Some custom metal fabrication projects involve fabrications from two or more alloys that would connect mechanically together somehow. And will interact mechanically on each other. Still, many of these projects could involve complex joint preparations, difficult to make welds and relatively advanced preparation prior welding.

Each custom metal fabrication project should involve very careful planning, testing, and researching stage. Additionally, sourcing of materials and parts in Covid – 19 environment could become problematic for custom metal fabricator with service reps working from home and carb site pick up. Even more difficult is sourcing of parts internationally due to low stock of many parts and back up orders volume increasing dramatically. Shipments take longer and we have to follow restrictive procedures for shipped parts’ utilization. Once again, proper planning and perseverance maters in these days.

Preparation stage of custom metal fabrication for mold’s steel support

JW Portable Welding & Repair specializes in custom metal fabrication projects due to our technological capabilities as well as…. lack of interest from other fabricators to run such project. The preparation stage for the aluminum mold’s repair and mold’s steel support fabrication serves as excellent example of typical custom metal fabrication project. It has involved two metals, aluminum alloy and mild steel mechanically joint and interacting with each other.  The project lasted about 7 weeks at the end of 2020. The project main objective was to extend the utilization period of expensive aluminum mold and improve functionality of canoe’s forms making.

Preparation stages of our project

The preparation stage for this custom metal fabrication project involved:

  1. Analysis of aluminum mold’s damages and damages to old and substandard steel structure supporting the mold,
  2. Planning solutions to the problems. Planning repair of aluminum mold and design new steel structure that will support the old canoe’s mold,
  3. Sourcing internationally high-force manual toggle clamps and clamps’ testing,
  4. Aluminum alloy testing in order to write welding procedure for mold’s repair,
  5. Testing the welding of aluminum 3561 alloy with spool gun in specific setup
  6. Machining of aluminum alloy cuboids and designing the cuboid engagement with the ½ inch threaded rod and,

Each task mentioned above has involved significant research. That is why I thought it is necessary to share my experience in the preparation stage for custom metal fabrication project. In my opinion, planning the preparation stage of your custom metal project bears heavily on the whole project’s success. Moreover, it increases the variety of solutions to many challenges faced by custom metal fabricator and reduces the overall cost of the whole project.

You will find the analysis of damages to this aluminum mold and to its steel structure here. Additionally, you will find the solutions to the problems including aluminum mold’s repair and design of the new steel structure by clicking here. These two topics cover a very broad and detailed analysis and proposals that would exceed the content of this article. I also have not included testing for welding of aluminum mold 3561 with cuboids made from the same material since you can find the conclusion of this testing here.

Therefore, lets focus just on sourcing of parts and specific alloys as well as testing of them. Additionally, I will mention machining aspects of alloys and fabrication of subcomponents for your custom metal fabrication project.

Sourcing of parts for custom metal fabrication project – high power Italian toggle clamps.

The custom metal fabricator often deals with mechanical components. Definitely, a mechanical background such as ours (certified industrial millwright) helps in selection and installation of mechanical components.

Sometimes, finding parts for the custom metal fabrication project could become very challenging. First of all, the custom metal fabricator’s present suppliers may not carry the desired parts. Consequently, the fabricator must to look for a different supplier. Secondly, in specific industries these parts could be available only internationally and are available in limited quantity. Thirdly, the quality of these parts varies pending the supplying party and description on internet are rather vague.

Therefore, your learning curve regarding specific industry and parts used in this industry could become very steep. You will quickly find yourself dealing with material limitations due to operating conditions for your custom metal fabrication project. Therefore, custom metal fabricator should be familiar with analysis of flaws in part’s design. In my opinion, it really helps to set up some quality and price goals prior searching for more advanced parts.

Quality industrial toggle clamps

The high quality Italian clamps have provided desired force, drag, safety and convenience for squeezing canoe's aluminum mold
High quality Italian clamps on aluminum mold’s steel supporting structure. JW Portable Welding & Repair, London, Ontario, 2020.

In our case, we were looking for high quality, steel cast and high force, industrial toggle clamps. Although, internet helps in locating the distributors of industrial clamps the manufacturers of toggle clamps are not as easily found. In my search for heavy clamps, I had set up a few goals such as

  • the toggle clamp must have a long drag since I wanted to close significant gap between the aluminum mold’s lid and bottom mold. Therefore, I wanted to have a drag of at least ½ inch,
  • the toggle clamp had to be made from a casted steel and had to be a high-quality clamp. Casted steel behaves very well when heated up and then cooling down multiple times a day whereas thin-walled steel clamps develop cracks and after few months fall apart. Some of these cheaply made toggle clamps in my client’s manufacturing operation start falling apart after approximately a year. Not only these clamps developed cracks but also the tensioning mechanism stops working. Additionally, these low-quality toggle clamps after the while are rather difficult to disengage causing troubles for canoe form maker and his helpers.
  • at that time, I was not sure what the distance between the clamp and its latch would be therefore I was looking for a toggle clamp that would accommodate to significant variation of distances and,
  • I wanted to find a clamp with a long comfortable handle. Many of toggle clamps have rather short handles that does not help in setting the clamp up.

I have intended to buy one sample or samples and then test them against multiple criteria. Then, I wanted to select the best clamp for my client.

Finding suppliers for high quality industrial toggle clamps

In our case, we have had some experience buying parts from Asian countries and from U.S. but we have not dealt with European suppliers yet. When searching high power manual clamps, we have found very limited number of suppliers that can supply cast steel clamps in Canadian market. Additionally, some suppliers were more comfortable to deal with low quantity shipments in case you need samples. 

I thought initially that I could get approximately 3 samples of different clamps and then after testing I would choose one. I was greatly mistaken. Not only I could not find a greater selection of heavy clamps, but I found that the quantity of clamps in the warehouses is not sufficient for the project. Without the clamps, our project was in trouble and I would not be able to continue. And my client would not be able to produce canoes. After many hours of research, I have chosen JWWINCO due to their comfortable service in Canada and an excellent and very informative website.

Testing of industrial toggle clamps

After the sample had arrived, we had begun to test the toggle clamp prior we were going to order more clamps. In clamping business testing of clamps is crucial. In sample clamp the handle was too short, pull was too little, but the drag was within our target. We have also tested the clamp’s setup for unintentional opening. The client experienced unintentional opening of the clamps in variety of situations and therefore all clamp’s handles had to be wired to prohibit the opening of clamps during the rotations in oven and in cooler.

We have tested this clamp for variety of latch plane positions in comparison to plane of clamp’s position. Moreover, we have tested this toggle clamp for variety of tensioning setup and then drag effect. The testing of unintentional opening was paramount. Additionally, we have conducted a few angular tests with conclusions that surprised us even more. I would like to underscore here that if you want to install clamps for your project, testing of them is a key to success.

Still more testing of industrial toggle clamps

After the evaluation of all tests we have decided to order another sample that would have a larger pull force and would have a locking device against the unintentional opening. The new sample made our target for all features except the locking device. The locking device, in opinion of client’s technicians and mine, would not sustain continues heating and cooling as well as any resin leak. Finally, we have reached our decision to order proper toggle clamps without locking device but with variety of U-bolts due to unknown distance between latch and the clamp.

Tests’ results contribute to project’s success

Overall, the multiple tests had served as well prior positioning the toggle clamps on the aluminum mold support’s structure. The tests of these clamps have also helped me to design the steel structure in such a way that toggle clamps would not open unintentionally. This was extremely important to my client since opening of toggle clamp in the oven can damage the oven and the aluminum cast.

In conclusion of the clamps’ issue, I highly recommend to any custom metal fabricator testing of clamps and in fact testing of any device that will play an important role in your custom metal fabrication project. Proper testing of the device and then the evaluation of tests will develop a clear picture of device limitations as well as device positive attributes. Proper testing will provide important information how to minimize limitations’ effect on the performance of the device. Moreover, proper testing will provide the clues to potential modification of the device in order to meet your specific designs.

Testing of metal alloys for custom metal fabrication project

Hundreds of clients asked me if I can weld this metal, but they would not tell me what it is. Most of custom metal fabricators were asked the same question many times. Well, you can approach the procedure in the long way or the proper way. The long way involves number of tryouts with variety of welding rods and wires and usually ends up damaging the material. The proper way involves material testing. And, I highly recommend the material testing way.

Testing of alloy materials creates assurance of proper welding procedure development. In my case, the client did not have any information regarding the aluminum alloy of this casted aluminum mold. Since I was planning to replace the step -ups of the lid with welded cuboids and I have expected to do other minor repair to the mold, I had to find out what kind of aluminum alloy I am dealing with. I had taken the sample from the thin aluminum rim of the lid and delivered it to Cambridge Materials Testing, prior committing to any welding. Their website is Cambridge Materials and I highly recommend this company for any material testing. They have very friendly and very knowledgeable people there. I also recommend delivering the sample to their facilities since it seams this will expedite the service.

Contribution of aluminum alloy testing

My earlier suspicions were confirmed, I was dealing 3561 aluminum alloy and basic information of this alloy for mechanical and thermal properties available at Matweb have become very useful in

  • developing the welding procedure for welding cuboids made from this alloy,
  • designing the shape of the cuboid since originally it supposed to be a cylinder,
  • and dealing with machinability problems

I also recommend testing alloys even if your client provides all specs of the alloy. It could have happened that client has made a mistake. Also, it is possible that alloy information has been passed from one buyer to the other buyer and in fact the material testing has never been done. Knowing the correct specifics of the alloy not only allows to search for info on this alloy on internet but also allows to properly inquire about welding procedure for the alloy as well. Asking for tricks of the trade and for professional advice never hurt anyone. Gathering all information prior welding is paramount for your custom metal fabrication project.

Sourcing the specific alloy for your custom metal fabrication

These are 3 ingots of 3561 aluminum alloy that will be machined into cuboids. The irregular shape of ingots makes and alloy physical properties make machining more difficult. JW Portable Welding & Repair, London, Ontario, 2020.
3 aluminum ingots purchased from a small foundry. JW Portable Welding & Repair. London, Ontario, 2020.

Sourcing of specific alloy for your custom metal fabrication project could become challenging. Buying 3561 alloy was not anything like going to the store and buying a piece of metal. The 3561-aluminum alloy is a casting alloy therefore the small aluminum foundries buy this alloy in form ingots. Then these small foundries make the castings from this aluminum alloy. Generally speaking, the 3561-aluminum alloy is not sold in form of angles, flatbars, rods, channels and beams. Consequently, you are not able to buy it in a traditional metal store.

I always believe that when there is a will there is a way. After a few calls placed to small foundries in Ontario that are dealing with aluminum, I finally have found an owner who was willing to sell me 3 ingots of 3561-aluminum alloy.

Producing components for your custom metal fabrication project

The custom metal fabrication project often demands custom machining of alloys prior their installation to your project’s structure. Once again, I highly recommend testing of these custom-made parts that should include also measuring them. It is also very important to realize that if you weld some of these custom parts, they will become non-removable since removing them will cause their distortion. Therefore, proper measuring and then fitting them to the existing project’s structure is very important.

The next step was to produce the cuboids from ingots of 3561 aluminum alloy. According to Matweb    the machinability of this alloy is only 50%. It simply means that machinists will have problems to machine this alloy into different shapes. I know a machining shop, St Thomas Tool & Die, that machine aluminum and are known in the industry. I gave them the 2 ingots that are chunks of irregularly shaped aluminum alloy and I asked them to make me these blocks.

Machinability of 3561 aluminum alloy

Well, they have struggle to make them since 50% machinability means that machinist have to do it very slowly unless the metal is frozen, and they were dealing with the worst-case scenario which was an irregular shape of this alloy. However, after a reasonable time, machining was finished. I have also learned that making a cuboid from this alloy is much cheaper than making cylinder shapes. Well, even though I would have preferred to weld cylinder shapes to the casting. I finally have settled for cuboid. Well, the price difference was significant.

We have inserted threaded rods into aluminum cuboids to attach steel fabrication structure to canoe's aluminum mold. JW Portable Welding &  Repair. London, Ontario, 2020.
Pile of threaded rods with rings welded at the end. JW Portable Welding & Repair. London, Ontario, 2020.

Many of custom metal fabrication projects also require fabricating many sub-components. I would call this process rather precision fabrication since it is a paramount for these components to be the same. I also recommend to first make a jig for these components’ precision fabrication. Even though, you will spend some time to make such jig the components fabricated based on this jig will be the same.

Summary, preparation stage for custom metal fabrication project

 The preparation stage for custom metal fabrication project requires project planning and extensive testing of all custom metals, and all parts used in the project. The fabricator must commit to search and acquire information from reliable sources. Additionally, the fabricator must be able to draw conclusions from in-shop testing. And it must incorporate the conclusions of tests to the design of a custom metal fabrication. In essence, the preparation stage for custom metal welding project is much more complicated and complex than a preparation stage for a steel fabrication project. Consequently, the fabricator for the custom metal fabrication project usually requires compensation for the project’s preparation stage.

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