Transom Repair - Uneven after grinding

pjdunn

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Apr 12, 2016
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2
Working on a restore - first time. Boat is nearly finished with grinding except for the transom area. I was a bit too aggressive with removing the transom wood and am left with uneven spots (high/low) all over the transom "face" after grinding. This is on an '89 Maxum 2000 SC (I/O).

Not sure how to go about building the thickness back up while getting it even once again so that I can properly apply/bond the new transom board. SOS!
 

Frey0357

Petty Officer 1st Class
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Mar 13, 2014
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313
Hello there PJDunn. Welcome! While I am not the person to provide your answer, a photo will greatly help those here that can help you. I would recommend a free Photobucket account then simply copy/paste your photo onto the forum and others will chime right in with help!

Good luck with your project~!
Frey
 

JASinIL2006

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Feb 10, 2012
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How much variation are you talking about? On mine, there was some variation in thickness after grinding -- I think it would be impossible (for me, anyway) to get it perfectly smooth and uniform using a grinder.

When I installed my transom, I trowelled on the peanut butter to adhere the transom core to the hull. I put it on really thick and allowed it to ooze out of relief holes (3/8" or 1/2") drilled through the wood as I slowly tightened the clamps. As I tightened, I checked the thickness at the keyhole using a set of calipers. When I hit my desired thickness (just a hair over 2") all the way around the keyhole, I stopped and let the PB cure. Worked really well. At that point, if there are minor variations, you can use layers of 1708 or CSM to build up some areas. In my case, I didn't need to mess with doing that.

Hope this helps...
 

Rick Stephens

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Aug 13, 2013
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And I, like JAS, did similar, if a little different. I troweled on the peanut butter as well, but I used a transom plate made of 2 sheets of 3/4 ply PB'd together. So I pulled that tight to the transom with a couple clamps made by running 2X4s across the inside and outside with a piece of all-thread connecting them through the keyhole. After that set, I epoxied on 5 or 6 layers of 1708 cloth on the inside until I got my desired thickness. You should check that you have uniform thickness around the keyhole, the only place that matters, as you clamp. I had to add a couple metal c-clamps near the bottom to get it fairly even, then had to sand just a little bit to level it to the gimbal before install.

best of luck on the build.
 

JASinIL2006

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And I, like JAS, did similar, if a little different. I troweled on the peanut butter as well, but I used a transom plate made of 2 sheets of 3/4 ply PB'd together. So I pulled that tight to the transom with a couple clamps made by running 2X4s across the inside and outside with a piece of all-thread connecting them through the keyhole. After that set, I epoxied on 5 or 6 layers of 1708 cloth on the inside until I got my desired thickness. You should check that you have uniform thickness around the keyhole, the only place that matters, as you clamp. I had to add a couple metal c-clamps near the bottom to get it fairly even, then had to sand just a little bit to level it to the gimbal before install.

best of luck on the build.

What Rick describes above is actually pretty close to what I did! I only added a couple of layers of 1708, though. My transom plate was 2 sheets of 3/4" pre-glued together also. That's about the only way I could imagine doing it. :thumb:

I have some discussion of my transom core installation starting about post #50 of my restoration thread (see link in my signature below). In looking back at my thread, I realized I initially set my transom thickness at just a bit less than 2" before skinning it over with 1708.

Good luck!
 

alldodge

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Mar 8, 2009
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Note to remember, final thickness needs to be 2 to 2 1/4 inch where the transom assembly bolts up.

Transom Thickness.jpg
 

Woodonglass

Supreme Mariner
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Dec 29, 2009
Messages
25,924
Thickness and Parallelism is important. The PB should will fill the imperfection when you install the transom if you apply enuf. I would strongly advise using a 3/4" backer plate on the outside to ensure everything remains flat and true during the clamping process. If your "Divots" have made the outer skin fairly thin in spots it could cause bulges but with the backer plate this won't occur.
 

pjdunn

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Apr 12, 2016
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Ok, so from the sounds of it the imperfections on the inside can be filled with the PB with the wood over top and then if needed to get the thickness to the required measurement then to build up at that point.
 

DeepBlue2010

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Aug 19, 2010
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1,304
If you are talking about the type of irregularities in the surface of a golf ball, for example, as a result of grinding, then yes, gluing the transom to the skin will take care of. On the other hand, if you made deep gouges with the grinder, I would build those areas up with glass b4 installing the transom. Some would argue this might not be necessary, nonetheless,this is what I would do.
 
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