transom repair in glass boat

skinny1965

Petty Officer 2nd Class
Joined
Aug 3, 2010
Messages
148
ok so right now I just have one more layer of plywood to remove from my boat then clean up . and start to make my new wood transom

here is my question out to you guys I have been watching few vids and following a few guys online that have done this job one guy has used PL premium to bond his wood to the fibreglass hull. I was thinking of doing this it makes some sense to me I have used PL for few other projects including some wood to glass just much smaller area.

the open time would be great with the pl in compared to using polyester I will not use epoxy due to cost

so tell me why this would be a bad idea
 

Woodonglass

Supreme Mariner
Joined
Dec 29, 2009
Messages
25,924
Re: transom repair in glass boat

As long as you're aware of the outgassing of the PL and the minimum 72 hour cure time and that poly resin does not adhere to any PL residue then there is no problem. If you abide by all of these you should be just fine. It's also important to get 100% coverage to avoid voids and air pockets. 3/8" trowel to spread the adhesive in a grid pattern on both the transom and the skin would be my recommendation.
 
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skinny1965

Petty Officer 2nd Class
Joined
Aug 3, 2010
Messages
148
Re: transom repair in glass boat

what is the out gassing is that all done in the 72hr
i'm thinking i could spread it around but leave a bit at the edges to allow me to tab in with glass
my concern is open time and not getting the new wood in before things start to kick off
I'm told I have maybe a 20 min working time
 

Bob_VT

Moderator & Unofficial iBoats Historian
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May 19, 2001
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26,019
Re: transom repair in glass boat

You will find that fiberglass and PL do not get along UNTIL the PL is starting to really cure. So if you attach something together and then want to use fiberglass to tab that to the hull...... you should wait or you can have a mess on your hands....... such as the fiberglass resin will melt the PL....... ;)
 

jbcurt00

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Oct 25, 2011
Messages
24,829
Re: transom repair in glass boat

Bob & WOG are correct, PL isn't ideal for several reasons.

Lay a fat bead of PL along a corner or seam, and wait. As it starts to cure, it will off-gas & bubble. The bubbles can develop for 72hrs or longer, and when it bubbles, the PL joint isn't as substantial and tying the 2 pieces together as well as it should be. The bubbles must be smoothed, and once cured, PL is still gummy when you try to sand it smooth. The longer you wait past 72hrs, the less gummy it 'might' be. The heavier/thicker the bead, the longer it takes to fully cure, and the worse the bubbling.

I used to advocate using PL, primarily for the same reason you want to. I now recommend AGAINST it. Once you get to rebuilding, you don't want to do anything that costs you time and causes you to wait (3 days is the minimum, not the maximum). Plus once you get something bedded in the PL, you also have to make sure NOTHING moves until the PL is cured. If the hull flexes before it's cured, the PL bond could be broken, and the only way to fix it is to remove everything & start over.

W/ good daylight, temps & some good help, you could possibly mix resin filler for bedding the transom, install the transom, use the squeeze out for fillets, and completely glass in the transom in 1 day, lets say a Sat. Then get to work on the stringers on Sun.

Using PL on Sat, you can't even tab the transom until mid week (or later), and really shouldn't move the boat or be crawling around in it until the transom bedding is cured. Since the bulk of the transom bedding resin filler is hidden behind the plywood, there is very little air exposure. PL might take much longer to cure. So then a week later, on another Sat, you might be lucky to sand the PL off anything it got on you didn't intend to get it on, and glass the transom in place. A whole week 'lost'................
 

skinny1965

Petty Officer 2nd Class
Joined
Aug 3, 2010
Messages
148
Re: transom repair in glass boat

ok so had some time after work to do some stuff to the boat
I'm starting to grind the remaining wood off the transom. I have found what seems like some glass that has become unbonded and not sure how to deal with it.

also the first sheet of plywood that was adhered to the glass went down below what I want to call bunks. I will try to upload photos . any way I think I can dig out the wood from in here with out cutting out more stuff. but can I put these pieces in on their own and then the rest of the transom or should it be one piece which would meah I have to cut a bunch more out for clearance

IMG_1005.JPGIMG_1006.jpgIMG_1003.jpg
 
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