1/2" The Hard Way

The guys in the metal working group said I should use 1/2"... So I did. Sorta. LOL.

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After doing all of this and doing some testing I can tell you 3/8 plate would have been more than adequate. I used 3/8 plate and then bandaided

1/8" onto both sides. I cut it slightly smaller than the tang on the plate, and cut the holes slightly larger giving me a nice step to weld the three plates together.

I can tell I am going to need a little more practice and experimentaion before I weld this all in place, and weld on the sheet on the front. Welding 1/8 to 3/8 is quite an experience. Its all about gun angle.

Bob La Londe

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Reply to
Bob La Londe
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What is that? The bow of a boat? Where is the 1/2" plate you made? The ring on the front? The picture is small enough (and my eyes bad enough) that it's hard to see.

What's the size of that vertical member the ring is welded to? Is that's

3/8 or something smaller or larger?

Doesn't that make it 5/8 which is larger than 1/2?

Yeah, sounds like fun. :) I've not done a lot with a aluminum and nothing with aluminum material that large. But I have dealt with what happens when you try do a lap joint where the top material is far thinner than the base material. You can't get enough heat into the base, the top keeps getting too much heat and melting back from the weld which you then have to chase back. It can quickly turn the weld into a disaster.

The big trick I found for that situation is doing whatever you could to get good thermal contact between the the thin top and the thick base. Clamp it together hard - watch out for distorted shapes that introduced an air gap - do multiple small tacks to both hold it in place an act as a thermal bridge between the two pieces. If there is good thermal conductivity between the pieces, then the heat which goes into the top just radiates down to the base and they both heat up and melt at the same rate. At that point, the weld is mostly just filling in a fillet in a piece that is acting like a solid hunk of metal.

In memory, I've only delt with that situation for TIG and O/A. I should try that with my MIG and see what trouble I can get myself into. :)

Reply to
Curt Welch

ROFL. I can't believe I made that mistake. After all that precision measuring and cutting both pieces bow cap and bow eye fit perfectly (first try). I can't believe I can't add 3 and 2 and get 5. That is just too funny.

With this piece I clamped it together in a vise and slapped a welding clamp on the other side. It was tight, and it welded like bigger metal. I didn't figure that out until I was almost done though. I cranked up the welder and t worked really well. Putting in the 1/8" sheets to finish the bow is where I was worrying. I will take some of my scrap leftovers and experiment some more. What I found worked when I was doing it flat before I figured out to just crank up the machine was welding into the 3/8 and then stitch flowing into the 1/8. It was an abnormally wide bead in that area, but it looked good.

Bob La Londe

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Reply to
Bob La Londe

I beefed up the front of my BassMaster similarly one time. About ten minutes in, I realized 1/2" was serious overkill and went to the 3/8 1/4 1/8 combo. It was elephant strong.

Steve

Reply to
SteveB

I may actually have to redo that fancy vertical bow piece. I learned a really elegant way to put the sheet into shape and fit it, by making a partial thickness cut in the aluminum. Bending it, and then welding over the cut. Its a nicer looking bend than a brake even. My uncle who was in R&D for Donn Products and then USG forever suggested something else that led me to that idea. Then after I had done a couple test pieces my wife came out and said, "oh yeah. I knew how to do that from when I worked my way through college working in the assembly plant at General Motors." My wife the soft sciences type. LOL. I sure wish she had suggested it to me weeks ago. Would have saved me tons of headaches in my planning for this repair.

Reply to
Bob La Londe

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