DIY-1972 thunderbird shawnee tri-hull boat restoration-(after shop repair gone wrong)

[jarrpal001]

Re: DIY-1972 thunderbird shawnee tri-hull boat restoration-(after shop repair gone wr

if you take a look at the video you will notice the three part transom. should i do it the same way? was it done like this for weight? or should i just just cut out two full plywoods and glue them together then resin/csm? what filler was used for the fillet?

 

[Woodonglass]

Re: DIY-1972 thunderbird shawnee tri-hull boat restoration-(after shop repair gone wr

Nice video!!! Really helps to SEE what you see. I guarantee you that is NOT the factory transom. It has been replaced at one time in the past. The drawing I provided in an earlier post is exactly how most of the transoms on here are fabricated. You can Glue the two layers of 3/4" ply together with Titebond III glue and I guarantee they will not delaminate like that one did. That transom should not have come apart that easily. the wood was actually not that bad. The resin was applied poorly. You will do a better job if you follow the instructions given here on the forum. Your overall transom thickness should be 1 1/2" to 2" max. Depends on your motor mount.

 

[oops!]

Re: DIY-1972 thunderbird shawnee tri-hull boat restoration-(after shop repair gone wr

a three part transom is ONLY used when the hull curves ......other wise ....its a one part......far more stregnth.

i glass my transoms togeather......no glue......just glass and screws......never come apart.

the reason for the delamination on the transom in the vid.....is because they just glassed it......

when you glass a transom or any other price of wood for the first time......you cold cure the resin at 1.5%......and coat the wood......when that is tacky...just about cured but not hard......then you glass regular at 2%.....de lam will not occure......the wood will fail before the glass de lams.

cklick the link in my sig for a transom build....

if the boat is an i/o ...its 2 inches.....ob....1.5 inches thick

 

[jarrpal001]

Re: DIY-1972 thunderbird shawnee tri-hull boat restoration-(after shop repair gone wr

questions about rear transom skin:

 

[jarrpal001]

Re: DIY-1972 thunderbird shawnee tri-hull boat restoration-(after shop repair gone wr

Nice video!!! Really helps to SEE what you see. I guarantee you that is NOT the factory transom. It has been replaced at one time in the past. The drawing I provided in an earlier post is exactly how most of the transoms on here are fabricated. You can Glue the two layers of 3/4" ply together with Titebond III glue and I guarantee they will not delaminate like that one did. That transom should not have come apart that easily. the wood was actually not that bad. The resin was applied poorly. You will do a better job if you follow the instructions given here on the forum. Your overall transom thickness should be 1 1/2" to 2" max. Depends on your motor mount.

if you watch the video what do you think about my question about the skin?

 

[jarrpal001]

Re: DIY-1972 thunderbird shawnee tri-hull boat restoration-(after shop repair gone wr

i have another boat which the prior owner replaced the transom but only used csm. will it be a problem?

 

[zopperman]

Re: DIY-1972 thunderbird shawnee tri-hull boat restoration-(after shop repair gone wr

Yes.

 

[jarrpal001]

Re: DIY-1972 thunderbird shawnee tri-hull boat restoration-(after shop repair gone wr

Yes.

why exactly?

 

[zopperman]

Re: DIY-1972 thunderbird shawnee tri-hull boat restoration-(after shop repair gone wr

It's not structural enough. 1 layer of CSM isn't doing much. And someone who would take those shortcuts would be likely to take other shortcuts.

Your out skin is NOT too thin, but I don't see why you couldn't beef it up if you'd like.

 

[jarrpal001]

Re: DIY-1972 thunderbird shawnee tri-hull boat restoration-(after shop repair gone wr

It's not structural enough. 1 layer of CSM isn't doing much. And someone who would take those shortcuts would be likely to take other shortcuts.

Your out skin is NOT too thin, but I don't see why you couldn't beef it up if you'd like.

my other boat was recently restored but the person i bought it from did not use any 1708 or biaxial. he used about two to three layers of 1.5 csm. am i going to have to redo his work? or just add 1708 now?View attachment 123790View attachment 123791View attachment 123792View attachment 123793

 

[zopperman]

Re: DIY-1972 thunderbird shawnee tri-hull boat restoration-(after shop repair gone wr

Start a new thread for that boat...
I'd ruff it up with some 80 grit sandpaper or a grinder and then lay 2 layers of 1708 with a layer of cloth between them, one layer bigger than the last, both tabbed into the hull

 

[jarrpal001]

Re: DIY-1972 thunderbird shawnee tri-hull boat restoration-(after shop repair gone wr

Start a new thread for that boat...
I'd ruff it up with some 80 grit sandpaper or a grinder and then lay 2 layers of 1708 with a layer of cloth between them, one layer bigger than the last, both tabbed into the hull

ok i will

 

[jarrpal001]

Re: DIY-1972 thunderbird shawnee tri-hull boat restoration-(after shop repair gone wr

making peanut butter can i just chop 1.5 csm into smal pieces? the supplier i used doesnt have any 1/4 chopped csm til next week.

 

[zopperman]

Re: DIY-1972 thunderbird shawnee tri-hull boat restoration-(after shop repair gone wr

Yes, that's fine. I'd rip it, not cut it.

 

[jarrpal001]

Re: DIY-1972 thunderbird shawnee tri-hull boat restoration-(after shop repair gone wr

 

[Woodonglass]

Re: DIY-1972 thunderbird shawnee tri-hull boat restoration-(after shop repair gone wr

Couple of things. On your grinder, use a rubber band and wrap a 3M scotchbrite pad around the vent holes to act as a filter to filter out the dust and it will make your grinder last longer. Second, on the transom just use a couple of layers of 1.5 oz CSM and resin to patch ove the thin spot. Note: Use your hands to tear out the patches. This will leave a "Hairy" edge and make it easier to feather and blend and smooth. First patch should just fit the area, second should be twice as big as the first. Mix some MicroBallons with your resin to make a fairing compound to finish it off with then sand and fair.

 

[jarrpal001]

Re: DIY-1972 thunderbird shawnee tri-hull boat restoration-(after shop repair gone wr

Second, on the transom just use a couple of layers of 1.5 oz CSM and resin to patch ove the thin spot. Note: Use your hands to tear out the patches. This will leave a "Hairy" edge and make it easier to feather and blend and smooth. First patch should just fit the area, second should be twice as big as the first. Mix some MicroBallons with your resin to make a fairing compound to finish it off with then sand and fair.

can i use pb instead?

 

[Woodonglass]

Re: DIY-1972 thunderbird shawnee tri-hull boat restoration-(after shop repair gone wr

I suppose you could, but I would use the CSM. Up to you. Whatever you use make sure to wipe it down with Acetone first.

 

[jarrpal001]

Re: DIY-1972 thunderbird shawnee tri-hull boat restoration-(after shop repair gone wr

I suppose you could, but I would use the CSM. Up to you. Whatever you use make sure to wipe it down with Acetone first.

i believe i have to remove some of the gelcoat in order to repair the fiberglass. what grit should i use to feather out the gelcoat?

 

[Woodonglass]

Re: DIY-1972 thunderbird shawnee tri-hull boat restoration-(after shop repair gone wr

60 grit worked great for me.