Couple questions from the fiberglassing noobie

[ayaresr]

As the title states, I'm new to fiberglass work. Finally got my resto project to the point where I am beginning to work on fiberglassing new stuff in. I did a coat of resin on the plywood I am using for stringers in order to seal it before I install it and start glassing it down. So far, this seems easy enough. My only question for now (more will certainly follow as I get further along in glassing) is, does the resin usually stay tacky for a few days? Its definitely adhered to the plywood just fine, the surface of it just seems tacky after 3 days. Enough so that if I lay some pine strips down to prop it up on, they stick to it when I lift it back up. If this is normal, no biggie, I can work with it as is. I just want to make sure I'm going about this right, and that I don't need to adjust how much hardener I am using or anything. Thanks for the help all!
Ryan

 

[88BLiner]

Re: Couple questions from the fiberglassing noobie

Hey there ayaresr first off welcome to iboats. i was just wondering if you are using poly or epoxy. It sounds to me like you need a little more hardener either way but i don't know a lot about poly. I am working with epoxy but yes i think you should call the people who sold you the product and ask them.

 

[ayaresr]

Re: Couple questions from the fiberglassing noobie

I'm using poly here. See any problem moving forward with putting the wood in if its a bit tacky? Like I said, it seems to have adhered just fine to the plywood.
Ryan

 

[Cadwelder]

Re: Couple questions from the fiberglassing noobie

It's fine for the resin to be a little tacky for a few days...actually best, as it helps the next layer adhere well. Now with that said it should be "tacky" not wet. Just check your mix ratio on the product recommendations you have and you'll be fine.

I take it your using "unwaxed resin" correct? You should be....

 

[ayaresr]

Re: Couple questions from the fiberglassing noobie

I did double check the ratio before my second batch, and it was correct. It definitely isn't wet, can't leave fingerprints in it or anything, so it is a good hard layer. And yes, I'm working with unwaxed. I appreciate the help and the reinforcement that what I am doing seems to be correct. Back to the jigsaw to cut a few more pieces before I mix up another round.
Thanks again!

 

[Woodonglass]

Re: Couple questions from the fiberglassing noobie

You DID put on a layer of CSM mat correct??

 

[ayaresr]

Re: Couple questions from the fiberglassing noobie

I did use CSM. Looking like I way underestimated how much CSM I will need for this though, as I'm still coming across more that I'd rather rip out and replace. Is it possible to get away with just resin to seal the wood, then the mat to install in the hull, or had I best order more mat before I run out?

 

[Woodonglass]

Re: Couple questions from the fiberglassing noobie

Resin without mat is WORTHLESS it will harden and crack open and allow water in. Nope when you're using Poly resin you MUST use the CSM.

 

[ayaresr]

Re: Couple questions from the fiberglassing noobie

Ok, kinda figured there was a reason for laying the mat in the sealing process...off to order some more. Got enough on hand to keep me busy for now, but that's not going to see me through the end of this project.

 

[Cadwelder]

Re: Couple questions from the fiberglassing noobie

Now hang on, you're just pretreating the wood right? You don't need CSM to pretreat with, just for the first application. The first coat of resin is just to prevent dry spots from forming in your first layer. Pretreat your wood and while it's tacky, start glassing it in....layer of matt then whatever cloth you're using...

 

[Woodonglass]

Re: Couple questions from the fiberglassing noobie

Correct the mat goes on AFTER the wood is coated and dry with the first layer of resin. Sorry if I confused the situation. But I am just an OLD DUMB OKIE!!!

 

[Cadwelder]

Re: Couple questions from the fiberglassing noobie

Well, Why would you coat the wood if your NOT going to lay mat???

I've preteated wood several days in advance before....don't hurt anything.

 

[ayaresr]

Re: Couple questions from the fiberglassing noobie

Ok, so pretreat with resin, dry, recoat and apply mat while wet, and enough resin rolled over the mat just till it disappears, no more, no less...sound like I've got it right?

 

[Cadwelder]

Re: Couple questions from the fiberglassing noobie

You got it....and the precoat can be tacky when you start the lay up...like I said before its fine.

Good luck.

 

[ayaresr]

Re: Couple questions from the fiberglassing noobie

Told ya guys I'd be back with more questions on this project. As I've been ripping the old wood out of the stringers, I have been doing the best I can to leave the glass that ran the sides of it intact as a means of lining up and measuring for the new wood. I'm close to the point of starting with mat and securing this stuff down. On what remains of the old glass, I still have wood stuck to the insides of some of it. My question here is, should I go ahead and cut the old glass down to the hull now that I have the wood set and sized where I need it, or would it be ok to resin the wood, clamp the old glass back into place until it sets (scuffing and wiping down with acetone first), and then laying new resin and mat overtop of this? I'm thinking with remnants of wood lam still stuck to the old glass, its not going to adhere as well as if I cut it down and start fresh at the hull with my new mat. Thoughts?
Thanks again,
Ryan

 

[Woodonglass]

Re: Couple questions from the fiberglassing noobie

You're thinking RIGHT! Grind it ALL OFF!!!

 

[oops!]

Re: Couple questions from the fiberglassing noobie

ok guys .....just a few things here..

1. unwaxed resin will remain tacky for days even when the gook is cured.
waxed resin will not be tacky.

2. when treating wood, the best is to coat the wood thick with resin. let it allmost cure, (sticky but not hard) then using waxed resin.....lay your csm and glass as normal.

the second waxed layer will form a water penatration barrier.

to the OP....do not freak out thinking you are doing it wrong,,,,,you will be just fine,,,,,the above method is the best case scenario....but the way you have done it .....is just fine.

this method is great for glassing under your deck.
however, if expecting to add gell or another layer of glass over the first layer, the wax will have to be ground off the top before adding another layer of poly based stuff. (resin, glass or gellcoat).

waxed resin is a top coat.....unwaxed is a laminating resin.


about your stringers and the channels you have left.....some first timers leave them in.....but the only advantage you get there is to hold the new strings in place.

the main drawback of this method is that it is impossible to get a good bond of the old glass to the new wood of the stringers, it is impossible to prep the surface of the old glass properly, when working in a one inch channel 5 inches deep!

grind off the old glass right down to the hull.......then re glass in the new stringers.
you will have a good bond, and the stringers will be properly installed, ready for foam and floor.

cheers
oops