New transom keyhole area not as flat as I thought

[Jimmy H.]

Re: New transom keyhole area not as flat as I thought

1st attempt was weak, didn't even budge. (four wimpy wood clamps)

2nd attempt was better and actually moved the gap to 2/16" until the wooden brace snapped. (winch with steel cable)

3rd attempt so far I have it moved to within 3/32" with 5/8" threaded rods and multiple 2x4's on edge. I would have used steel bars if I could have sourced them quicker. I'm leaving it this way over night to see if the force on it moves it a bit further. I had to use all my force with the pipe wrench to move these nuts now. Transom is so strong with hardly any glass yet.

Not sure if I can flatten it as much as I wished. But the closer I get the less gel coat I can use to level it out so should work out fine in the end.

 

[mrdjflores]

Re: New transom keyhole area not as flat as I thought

since the wood is already bonded to the hull, i have a feeling it will just go back to it's original shape once the clamps are removed

 

[jbcurt00]

Re: New transom keyhole area not as flat as I thought

since the wood is already bonded to the hull, i have a feeling it will just go back to it's original shape once the clamps are removed

Yep, the original out of spec shape. It's cured w/ that cup in it. I think you'll be adding & grinding glass on both sides until it's flat across the keyhole. Take care to make sure it's perpendicular & square to the centerline of the boat & not skewed as you add & grind to make it flat.

 

[Jimmy H.]

Re: New transom keyhole area not as flat as I thought

I know, your right. What are thoughts on a gel coat layer between 3/16" - 1/4" thick? Is that too much of it? That would be the max thickness at the deepest point only if I fill it in back there...

 

[Trooper82]

Re: New transom keyhole area not as flat as I thought

I'm no gel expert, but I'd think that would be too thick...and would take many coats to get that thick...why can't you just sand the inside say 3 or 4 inches around perimeter of the key hole...to get things trued up..then make a template with a sheet of plastic drop to cut your glass to refit shape...and build up layers to get things back to hieght so it wouldn't look odd inside? if that makes sense....

 

[jbcurt00]

Re: New transom keyhole area not as flat as I thought

I agree with Trooper, to not use a thick layer of gelcoat. And I think I agree w/ his plan of attack. I'm not fully functioning yet :facepalm:

There will be a fair amount of pressure against the transom bolting the motor & outdrive thru it. Now regularly stress cycle the area as you throttle up & down, and apply various amounts of torque while crossing wakes & etc.

I'd compare using a thick layer of just gelcoat to using poly resin w/ out the glass.... Not as strong as poly resin & glass, and likely to crack.

 

[Jimmy H.]

Re: New transom keyhole area not as flat as I thought

why can't you just sand the inside say 3 or 4 inches around perimeter of the key hole...to get things trued up..then make a template with a sheet of plastic drop to cut your glass to refit shape...and build up layers to get things back to hieght so it wouldn't look odd inside? if that makes sense....

I think I follow, what about the outer hull? Do you all suggest to add more glass? Could I rough scuff the gel coat and add more glass or is it critical I sand away the gel coat down to the hull and then add glass to flatten?

 

[Woodonglass]

Re: New transom keyhole area not as flat as I thought

This MUST be a structural fix. Not cosmetic. Grind down to fresh glass on the outside and lay new glass that can be ground flat and surfaced to the appropriate required thickness for the outdrive. This is critical for the proper installation of the motor and outdrive. Do Not cobble this up. Make it right and as precise as you can. You won't regret it in the long run.

 

[Jimmy H.]

Re: New transom keyhole area not as flat as I thought

This MUST be a structural fix. Not cosmetic. Grind down to fresh glass on the outside and lay new glass that can be ground flat and surfaced to the appropriate required thickness for the outdrive. This is critical for the proper installation of the motor and outdrive. Do Not cobble this up. Make it right and as precise as you can. You won't regret it in the long run.

Thanks wood, I'll make it right and do it proper. That's the way it's gotta be.
thanks everyone involved for your help.
James

 

[Trooper82]

Re: New transom keyhole area not as flat as I thought

So how have you made out on this?

 

[Jimmy H.]

Re: New transom keyhole area not as flat as I thought

Hey Trooper, so far so good. I glassed a bit too much and ended up way thicker than I needed but no big deal I just had to grind a bit more to get down to proper flatness. Things are real close right now, I'm taking it real slow grinding a bit at a time to get it perfect. I think soon I'll be back working inside the boat. Just glad I have it in the garage now with the furnace so I dont need to worry about temperature and moisture!!

 

[Jimmy H.]

Re: New transom keyhole area not as flat as I thought

I have the outer hull very flat right now but I am having some trouble matching up the flatness on the inner side of the transom. The inner transom plate rocks slightly and I keep trying to correct it with not much luck. I've made a sort of jig which measures 2 & 1/16" thick to try and be parallel with the outer hull. Is it best I just keep grinding until my jig slides smooth in all areas? Any thoughts or better ideas? All this because of the way I clamped in the transom, I must have at least 12 hours extra time so far trying to flatten this out.

This is how the inner looks now.

This is the jig for checking thickness

The jig is still tight in a few spots so I know it is not exactly even yet.
Thanks

 

[Alwhite00]

Re: New transom keyhole area not as flat as I thought

Looks like you are on the right track with the fix. I am thinking you should have used a couple pieces of 3/4" ply instead of the 3/8" & 1/4" - I think the thinner stuff is just not as flat as the 3/4" and once you were glued up you were pretty much committed to whatever "warp" that was present in the wood.

Looking good.

LK

 

[Jimmy H.]

Re: New transom keyhole area not as flat as I thought

Well am ending the weekend on a good note! I took a break for a few hours and couldn't stop but wonder why things weren't flat. I geared up and went back at it. After using the jig all around the keyhole and making sure the thickness was even I held the inner plate to the transom and it still wobbled... What? Why?
Then I saw why... I inspected it before but I never noticed. Maybe all the dust on my glasses??

Can you see what the problem is??

One of the ground wires was fed through to the other side and I never saw it.

A close up, sorry a bit blurry.

Thanks for everyones input and help on this one. I will get back to my original thread and continue to move forward instead of backwards I hope!
Jimmy

 

[Decker83]

Re: New transom keyhole area not as flat as I thought

Looks like you have it all going your way. Great work. I would guess you are allowing for the new glass and gel coat in your thicknes jig.
Glad to see you have it on the down hill side. Keep up all the good work.

 

[Jimmy H.]

Re: New transom keyhole area not as flat as I thought

I would guess you are allowing for the new glass and gel coat in your thicknes jig.

Thanks Decker. You bet, I am expecting to be a hair under 2.25" when complete.