what do you think of a tubular frame aluminum transon insert?

bob johnson

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I am trying to figure a way to build my Holiday with out wood...if possible. I have a miller Mig welder and can weld up aluminum pretty easily.

I am thinking of framing up an insert made of 1.5" sq aluminum tube that would look like this:

257nh2o.jpg


the two legs in the middle either side of the center line would be solid aluminum bar( 5" wide) and they would be for extra support for the bolt hole pattern

any thought... I am thinking it might weigh about 65 lbs.

at the worst I could use 1-1/4 and sheath it in 1/8th aluminum...that would make it even stiffer

just the frame would cost me about $225.... for $560 I could get a solid composite transom board....


bob
 

gm280

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Jun 26, 2011
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I'm sure you can make a pretty solid feeling transom like that. But how does it actually attach to the hull all around. Those areas are where the stress is going to work the hardest. And how are you able to weld with a MIG setup? I have a very good MIG, but I thought a TIG setup was for aluminum... IDK :noidea:
 

bob johnson

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well it just slides down into place and the outer transom skin contacts the one side... then I could I might need to sheath the inside with something...... thinking about it now, I might have to make sure all the screw holes go through the 1. 5" tubing...instead of the usually places around the transom cut out...

bob
 

GoldDuster360

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They already make something that might work out much better and cost about the same, it's called aluminum honeycomb. I remember ordering that stuff at both aircraft manufacturers I worked for years ago. They used it in allot of structural applications, seat frames, firewalls, floors, can't imagine they don't have one graded that will support an outboard. Probably better than wood, but I tell you what, if I ever replace mine it's going to get a marine grade ply soaked in west system epoxy, will be the last transom that boat will ever need.
 

Watermann

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Something tells me that you would have a domino effect by changing such an important structural part of the boat and everything that goes on it. Some of the things I've seen hanging off the transoms are stern eyes, pitot tube, transducers, knee brace(s), tabs, kicker motor, swim ladder or platform, spashwell and I'm sure other things that shouldn't be there. You drill holes through tubing and it's going to fail so the way I see it the whole transom has to be a solid piece.
 
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bob johnson

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Feb 25, 2009
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Something tells me that you would have a domino effect by changing such an important structural part of the boat and everything that goes on it. Some of the things I've seen hanging off the transoms are stern eyes, pitot tube, transducers, knee brace(s), tabs, kicker motor, swim ladder or platform, spashwell and I'm sure other things that shouldn't be there. You drill holes through tubing and it's going to fail so the way I see it the whole transom has to be a solid piece.

yeah the more I think about it, the more I see that it would have to have a sheet of aluminum on each side of the frame...and at 1/8th" it would be fine. since I have so many projects, I might just take the easy wood way!! I am 57.....when I am 70, I doubt Ill be using the boat much! ha ha...so wood it is!

bob
 

gm280

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Bob, I can testify that I just removed a totally rotted out wood transom that I can't see how anything was staying on it anymore. And I layered up two pieces of 3/4" exterior grade plywood and did the polyester layups on both sides and then PBed that to the grinded out transom area. And I am absolutely amazing to see and feel how solid it is now. I don't believe a sledge hammer would move it now... There is ZERO flex to that transom. So wood really isn't that bad an idea. And I can easily see that transom lasting long after I'm gone!
 

Decker83

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Apr 5, 2011
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I'm sure you can make a pretty solid feeling transom like that. But how does it actually attach to the hull all around. Those areas are where the stress is going to work the hardest. And how are you able to weld with a MIG setup? I have a very good MIG, but I thought a TIG setup was for aluminum... IDK :noidea:
Tig is used all the time in aluminum welding.. With the right Mig welder you can add a spool gun and weld aluminum. Also you need the right gas too..
 
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