Help with bending a metal transom

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PC52

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Oct 21, 2020
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Hi,
I am currently building Mamoli 1:54 Le Coureur and I hit a snag. The instructions say to bend the transom. How does one bend a metal transom without breaking it?
The metal type is not mentioned :-(
I contacted Dusek who now owns the Mamoli catalogue. I gave them the info they requested but i am yet to receive a response.
Any suggestion would help.
Here are two pics to illustrate the curve that the transom needs to match. Thank you in advance :)
transom1.jpg


transom2.jpg
 
I had same problems with Mamoli white metal parts. The parts will break when trying to bend them. I managed to bend them gradually heating them with soldering iron. Make sure you don’t overheat them over yield point as it will melt.
 
Thank you for such a quick response Y.T. is there a step by step tutorial somewhere? I have no experience with soldering irons. I guess I'll have to buy one.
 
I understand. Soldering iron is not the only source of heat. We have candle, stove top and so on. Just be careful with delivering the heat from any source as if your part melts it is gone. Here what they write for white metal melting point. Note that your part can be made of alloy of much lower or higher melting point.

white metal alloy may include antimony, tin, lead, cadmium, bismuth, and zinc (some of which are quite toxic). Not all of these metals are found in all white metal alloys. Metals are mixed to achieve a desired goal or need. As an example, a base metal for jewellery needs to be castable, polishable, have good flow characteristics, have the ability to cast fine detail without an excessive amount of porosity and cast at between 230 and 300 °C (446 and 572 °F).
 
How to bend it uniformly will take some kind of jig I suppose, but to make sure you don't go over the melting point, but get it hot enough to yield plastically, you might try a temperature indicating "crayon" like this. They vary, but the dull marks made will turn shiney, or clear or change noticeably when they reach the advertised temperature, usually quite accurately. With these you can make marks in several places on the back and ensure that you don't encroach on melting temp anywhere.
https://www.amazon.ca/Markal-Thermo...+sticks&qid=1608994211&sr=8-1&tag=googcana-20
 
epicdoom said:
I shape a wood block to the exact contour, then I use a metal clamp to clamp the piece to the block in the center. heat each side with a small pencil torch and bend the ends into the shape needed, clamp ends till cool.
Click to expand...
I agree, the alternative is that you could gently heat the whole piece on a stove and lay it on the jig, Less is more as far as heat--just enough to make it flexible.
 
I agree with Thomas, start with heating the oven to 300 - 350 with the piece on a jig, let it heat for 20 minutes and gently press onto jig. If too much resistance, try 375. Don't make your jig from plywood as the glues could soften and melt then the pieces separate.
 
Not sure i responded properly to all the help that was so kindly provided.
I want to thank all those who gave me good advice. I indeed baked the transom for 20 minutes and bent it gently. Here are pics about the jig i created and the results.
Again thanks all!
transom and jig.jpgfinished transom.jpg
 
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