PL Question... What is it?

[mercurymang]

I have discovered a soft spot in my floor towards the rear and have decided that over the winter I am going to open it up and see what going on in there. I have already readied myself for the worst case scenario so I've doing some reading up on here so that when the time comes, i'll be prepared. One of the things I keep coming across is PB and PL. I know what PB is but I cant really seem to be able to tell exactly what PL is. I'm fairly sure it's a polyurethane substance but not sure where you get it. Does it come in tubes? Is it similar to Liquid Nails?

Forgive the newbie question but I think the time has come to figure this one out.

 

[TJS]

Re: PL Question... What is it?

Home Depot has it. Make sure you get the premium one(waterproof). Get the big tubes for the bigger caulk guns.

 

[mercurymang]

Re: PL Question... What is it?

Ok. So that's what it's called in the store? PL?

 

[matt167]

Re: PL Question... What is it?

PL-400 Subfloor adhesive also works. Both are listed as waterproof.. PL stands for Pro Line and is a Loctite product. It says PL right on the tube

 

[mercurymang]

Re: PL Question... What is it?

Ok, thanks Matt and TJS. I also read something about Epoxy will stick to PL but PL will not adhere to Epoxy. Do I have that right? If that's the case, how do you go about tabbing in a stringer that has been bedded and filleted in with PL?

 

[Pmccraney]

Re: PL Question... What is it?

Yes, it comes in tubes that look like caulking tubes. I believe Loctite makes it, but the tubes will say PL Premium running the length of the tube. In the big box stores it will be near the gorilla glue and other adhesives.

EDIT: Sorry, question was already answered by the time I hit submit.

 

[Woodonglass]

Re: PL Question... What is it?

It looks like this and I don't think epoxy will stick to it.

 

[mercurymang]

Re: PL Question... What is it?

Ok, so you wouldn't recommend bedding stringers with it?

 

[Pmccraney]

Re: PL Question... What is it?

Ok, so you wouldn't recommend bedding stringers with it?

Probably not - if you are using epoxy in your build. You can use an epoxy-based thickened resin for bedding, which we affectionately call "Peanut Butter" (similar consistency). Will be more expensive than PL, but more compatible with your build (if you are using epoxy). If you are using Polyester Resin for you glassing, go forth and conquer with PL.

 

[Woodonglass]

Re: PL Question... What is it?

No matter what resin you're using PL is tricky to use. It takes 72 hrs minimum for it to stop outgassing and allow you to start glassing. Still no guarantees it won't effect the resin. If you're careful with it and wait a long time and don't let it come in contact with the resin then you can use it. I used to use it but no longer. Just not worth it for me. PB is a much better way to go IMHO.

 

[JASinIL2006]

Re: PL Question... What is it?

Also, keep in mind that PL has a fairly lengthy cure time, while a thickened resin mixture (PB) will cure much more quickly and allow you to wrap your bedded stringers the same day, rather than having to wait several days for the PL to cure.

 

[mercurymang]

Re: PL Question... What is it?

Ok, I think I'm going to put the PL product out of my mind and if the need arises, I will go with epoxy. But, just for the sake or curiosity, how does one glass with it. It seems that it would be way to thick to apply to CSM or 1708. Maybe I'm thinking about it wrong. If so, let me know.

 

[matt167]

Re: PL Question... What is it?

You only use it for bedding in stringers and that type of thing. Can also laminate the transom together with it. You don't use it as a resin for fiberglass. Just stick it in your caulk gun and run a bead. If you use it for the transom, you will want a notched trowel and spread it.. You should have no issues with it if you do not rush and wait at least 4 days for the stuff to outgas and cure fully.. If your using epoxy, then don't use it but if your using poly resin, than it's safe

 

[GT1000000]

Re: PL Question... What is it?

The PL is generally just used as a glue, to bed the stringer to the hull, for example...then after it is fully cured, usually 72+ hours, the stringer is fileted and tabbed...
It has been discussed a couple of times here on the resto forum and while it is an acceptable way to glue/bed the stringers in place, there have been a couple of instances where the PL continued to "outgas" after putting the filet/CSM on top, and it caused some delamination problems...
Another use for it that has been tried with limited success is to use the PL as a filet material also...
For worry free bedding and fileting, it is better to use PB...you just have to get used to the shorter working times, but the main advantage, especially if using poly, is that as soon as it kicks, you can continue to move on...
On another note, you can use poly resin instead of epoxy and save about a third of the cost, plus if you decide to gel coat the deck, you will be able to with poly, not with epoxy...plus, your boat was most likely originally made with poly resin, so why spend the extra green...IMHO...

 

[mercurymang]

Re: PL Question... What is it?

Ok, so it looks like it really comes down to cost. Epoxy is the best stuff to use but it is more expensive than poly, correct. I have to admit that I think I have been confusing PL and Poly resin in my head:facepalm:. At any rate, I think I am getting this down, do I have it correct now?

 

[GT1000000]

Re: PL Question... What is it?

Yes, I think...
PL= PL Premium Construction Adhesive, used mostly in house construction...
PB= Peanut Butter: Thickened resin; can be made from epoxy or polyester resin; is thickened using one or more of the following:Cabosil/Aerosil, Micro-Balloons, Milled Fibers,; Not generally used due to water absorbing tendencies;Talc, Sawdust...there are others, but these are the most common...
Polyester Resin= Most boats built using it, fast working times Less expensive than Epoxy, Not generally considered as strong or as water proof...
Epoxy Resin= Higher costs, slower working times, generally only used on very high end boats, sailboats, racing boats, considered to be stronger and more water resistant than polyester...

If you really want to try and figure out all of this, go here and read through these stickies...
http://forums.iboats.com/boat-resto...r/how-tos-other-great-information-288451.html
http://forums.iboats.com/boat-resto...ake-fiberglass-information-thread-286013.html

Hope this helps clear some of it up, but we'll be here to answer and confuse...

 

[mercurymang]

Re: PL Question... What is it?

Thanks much guys. This clears up quite a few things.

BTW, I have a '74 Ebbtide. There's one other guy on here that has one and he was about half way through a rebuild but he hasn't posted in a while. If anyone else has one, let me know. As I said, I'll be tackling mine once boating season is over.

 

[bakerjw]

Re: PL Question... What is it?

IMHO you're better off with PB than with PL. USComposites has a real good price on Cabosil which is the foundation for PB. I also like to add chopped glass to mine to make it hairy. When I bedded my stringers, I was amazed at how strong the bond was between them and the hull.

I am also using epoxy rather than polyester resin. It is almost twice the cost, but the added strength and waterproof nature are something that were very important to me.

 

[britisher]

Re: PL Question... What is it?

I used PL adhesive on my full rebuild as well as poly resin rather than epoxy resin. I used the Friscoboater's SR rebuild thread as my guide and inspiration and it did not let me down. I sourced all my resin and other materials from US Composites as they are in FL like me. If you have a supplier nearer you where you can collect, then compare pricing carefully as you pay an eye watering UPS delivery surcharge on 5 gallon drums. It's true the PL does gas, so be careful how much you put down. It does take time to cure, BUT when you are installing stuff it also gives you wiggle time to make any final adjustments. With PB, it will go off pretty quickly, so your wiggle time is far less. When you are laying down a 12 foot stringer x 2, you need wiggle time. I didn't let the cure time frustrate me as in a rebuild there will always be something else you can be doing while it's curing. Good luck

 

[jasonbailey]

Re: PL Question... What is it?

So, not to hijack, but I'm getting ready to do a transom replacement, but if I use the PL to laminate the two sheets of 3/4" plywood together, and let them sit for 3 days before covering in glass, I should be ok?

It looks fairly simple to work with and as long as it is sealed up tight it looks like it should last a good long while.

My boat is 28 years old, if I follow the FriscoBoater methods it should be good for another 30, which would make me 73 when this needs to be done again.