pl or epoxy to attach transom to outer fiberglass skin?

On a few other sites of heard of people using pl to attach the transom to the outer fiberglass and also using pl to attach the stringers. Which is better pl or epoxy? Or does it depend on the boat size? I'm getting ready to put my transom ans stringers in a 27 foot cruiser

Re: pl or epoxy to attach transom to outer fiberglass skin?

I'd have no problem using PL Premium for that. No problem using epoxy either, except for the price, I'd just use which ever I have.

Re: pl or epoxy to attach transom to outer fiberglass skin?

Ayuh,... As long as you set up your clamping procedure before you start,...
I doubt there's Any difference that amounts to anything...

Re: pl or epoxy to attach transom to outer fiberglass skin?

I used PL and clamped it down tight.

Re: pl or epoxy to attach transom to outer fiberglass skin?

Using pl would just be easier. Me and Supernova fitted the new transom this morning. And it's tight fit getting the new transom below deck then pushed up against the outer skin. Also what is the working time of pl? My idea is to caulk it on the outer skin then take a notched troll to spread it out.

Re: pl or epoxy to attach transom to outer fiberglass skin?

lime4x4 said:

Also what is the working time of pl?

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I use PL Premium all the time in my job. It tends to 'skin over' after about 5 minutes, but the parts can be moved for at least an hour before the stuff starts to set.
From my experience, for the best bond you need to get the parts together pretty quickly- even if they're not exactly lined up. The key is to prevent that skin from forming. Once you've got it lined up and tight, WALK AWAY an don't disturb it for at least 3 days (but a week would be better).

BTW, have lots of ventilation and cleanup with lacquer thinner.

Re: pl or epoxy to attach transom to outer fiberglass skin?

lime4x4 said:

Using pl would just be easier. Me and Supernova fitted the new transom this morning. And it's tight fit getting the new transom below deck then pushed up against the outer skin. Also what is the working time of pl? My idea is to caulk it on the outer skin then take a notched troll to spread it out.

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That is exactly what I did. I had an old tile notch trowel and it worked out great. Check out my resto thread and it has a few pictures.

Re: pl or epoxy to attach transom to outer fiberglass skin?

PL Premium is plenty strong for attaching a transom. It's also cheap and convenient.

On the down side, it can take a long, long time to fully cure in larger blobs. It's also less strong than epoxy (dunno how it compares to poly resin).

Erik

Re: pl or epoxy to attach transom to outer fiberglass skin?

I used several tubes of PL. Just make sure everything is clean and dry. Use acetone to clean the glass. My transom is solid!

Re: pl or epoxy to attach transom to outer fiberglass skin?

One thing to take note of is that IF you get some water intrusion with pl or if everything is not dry when you put it on, it'll expand a bit - not a huge issue but something to be mindful of.

Re: pl or epoxy to attach transom to outer fiberglass skin?

It's not the cost it's what's going to be easier. With the new transom wood in the bilge and 2 guys it's very tight. I'd never be able to get epoxy on the transom wood without getting it on us and all over the boat till it's in place. The transom plate will help keep it tight to the outer fiberglass. Plus the inside will have atleast 3 layers of biaxle clothe attaching it to the transom and side of the hull

Re: pl or epoxy to attach transom to outer fiberglass skin?

Just finished my transom with PL..used a notched trowel..stuck together..screwed it..it sat for 1 week..its beautiful..have 2 layers resin w/ CM..ready to go..i approve

Re: pl or epoxy to attach transom to outer fiberglass skin?

lime4x4 said:

On a few other sites of heard of people using pl to attach the transom to the outer fiberglass and also using pl to attach the stringers. Which is better pl or epoxy? Or does it depend on the boat size? I'm getting ready to put my transom ans stringers in a 27 foot cruiser

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The simple truth is that epoxy is better. That is the question you asked. I know that many on this site advise using PL as an adhesive, but there are limitations that make it unsuitable for any kind of structural marine repair. Repairing stringers on a 27ft boat is an entirely different world from working on a 16ft tin can. That said I personally don't think PL is suitable for any boat.

I would contact Sea Ray and ask for their guidance. If the people at Sea Ray won't help call up the folks at West Systems. They will guide you through the proper way to do this repair even if you aren't using their product. That year and type of boat most likely used poly resin, however there are vinyl and epoxy boats out there and the wholesale advice of using poly on this site will eventually land somebody in a world of hurt if they don't know what they are dealing with.

The stringers and transom on a 27ft boat are under enough stress that the safety of yourself and your passengers depends on this repair being done properly and with respect for the original laminate schedule of the boat. A single part urethane adhesive designed for the construction industry is a risky move on a project like this.

There is a lot of good advice on this site. There is also a lot of dangerous advice on this site. Good luck.

Re: pl or epoxy to attach transom to outer fiberglass skin?

Shife said:

The simple truth is that epoxy is better. That is the question you asked. I know that many on this site advise using PL as an adhesive, but there are limitations that make it unsuitable for any kind of structural marine repair. Repairing stringers on a 27ft boat is an entirely different world from working on a 16ft tin can. That said I personally don't think PL is suitable for any boat.

I would contact Sea Ray and ask for their guidance. If the people at Sea Ray won't help call up the folks at West Systems. They will guide you through the proper way to do this repair even if you aren't using their product. That year and type of boat most likely used poly resin, however there are vinyl and epoxy boats out there and the wholesale advice of using poly on this site will eventually land somebody in a world of hurt if they don't know what they are dealing with.

The stringers and transom on a 27ft boat are under enough stress that the safety of yourself and your passengers depends on this repair being done properly and with respect for the original laminate schedule of the boat. A single part urethane adhesive designed for the construction industry is a risky move on a project like this.

There is a lot of good advice on this site. There is also a lot of dangerous advice on this site. Good luck.

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baloney.

Re: pl or epoxy to attach transom to outer fiberglass skin?

I know who to use epoxy. Epoxy would be my FIRST choice. But there is no way to apply epoxy to the transom wood without it getting every and pretty much of it will be wiped off the new transom wood. The only way to use epoxy correctly would be to cut the whole rear of the deck and upper transom skin. Which isn't going to happen

Re: pl or epoxy to attach transom to outer fiberglass skin?

lime4x4 said:

I know who to use epoxy. Epoxy would be my FIRST choice. But there is no way to apply epoxy to the transom wood without it getting every and pretty much of it will be wiped off the new transom wood. The only way to use epoxy correctly would be to cut the whole rear of the deck and upper transom skin. Which isn't going to happen

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I guess I'm not following what your problem with application would be. The physical properties of any 2-part can be modified with fillers, so trying to match the viscosity of PL would not be an issue if that's what you're after.

Re: pl or epoxy to attach transom to outer fiberglass skin?

usually when bonding you wet out both peices then apply thicken epoxy (pb) to one peice and clamp them together.Well the way my boat is setup for access i can't wet out the new transom wood.. The new transom wood goes down into the engine bilge at an angle and the side that goes against the outer transom fiberglass lays on the bottom of the hull. Then with the help of another person we have to lift up the new wood and at the sametime angle it into position. There is no way to wet out the transom wood

Re: pl or epoxy to attach transom to outer fiberglass skin?

lime4x4 said:

usually when bonding you wet out both peices then apply thicken epoxy (pb) to one peice and clamp them together.Well the way my boat is setup for access i can't wet out the new transom wood.. The new transom wood goes down into the engine bilge at an angle and the side that goes against the outer transom fiberglass lays on the bottom of the hull. Then with the help of another person we have to lift up the new wood and at the sametime angle it into position. There is no way to wet out the transom wood

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I've done a lot of composite repairs in a lot of cramped locations and I'm having a hard time trying to grasp why you can't wet this area out. Considering the comparitively poor bonding strength of PL, I don't get why you would want to use that over a 2-part.

Have you considered vacuum bagging?

Re: pl or epoxy to attach transom to outer fiberglass skin?

It sounds like you might need to clear more space to work on the transom replacement. If there's not enough space to wet it out, there's not enough space to replace it.

I have to agree there's a lot of dangerous advice on this site. "lot" is relative, there's a huge amount of good advice too, but every so often you run into someone who "has always done it X way" or is an "expert" and tells you so, or someone who wants so badly to be part of this great community that they hand out advice they're not really qualified to give.

Fortunately the fact that folks here usually build boats stronger than factory spec gives us a great safety margin, so even dumb things won't necessarily kill you.

Back to topic, even though PL has some great convenience points, there's a reason pro builders use epoxy and poly resin. Can you imagine them NOT moving to PL if it was comparable? It's cheaper, some of them are going out of business now because of lack of money.. I think they'd use it if it worked.

Erik