Is a waxed topcoat NEEDED for a laminating resin?

HopinImFloatin · Jun 10, 2011

After many months of stalking iboats forums and learning much, I still have an unanswered question. Is a waxed finish resin or gelcoat needed over a laminating resin layup. I ask this because I finally began the removal of the deck and rotten stringers in my 1987 Cobia 189xl. I have much of the material that I will need including 5 gallons of unwaxed resin. I was planning to use this for the patching of the stringers and the waterproofing of the underside of the deck. I realize it stays tacky but I want that due to the fact I have never glassed this much at one time and dont feel I can perform the stringer repairs in one large multiple layup and am not very fond of grinding

. I guess the real question is does this need to be tack free before any bonding (gluing the deck down) can be done? Also some of the stringer repairs will carry somewhat into the open bilge area around the motor mounts and will be exposed. Does it ever become totally tack free and if so how long could/would it take? I was planning to use a finish resin for the topside of the deck as a final layer. Thanks for listening to me ramble.

Woodonglass · Jun 10, 2011

Re: Is a waxed topcoat NEEDED for a laminating resin?

Welcome to the iBoats Dry Dock!

Nope not required. In fact you really don't want it for your stringers, and transom and anything below deck due to exactly what you described. If it had wax in it to make it NOT tacky then you would have to sand it off to apply another layer. How to you plan to finish the topside of your Deck?

HopinImFloatin · Jun 10, 2011

Re: Is a waxed topcoat NEEDED for a laminating resin?

Thanks for the speedy reply! Glad I didnt go to bed yet

. After reading many posts, including many from yourself, I will be going with a first layer of csm followed by a layer of heavy roving (may be 24oz, not sure but its very heavy) then another layer of csm to smooth things out if needed. Carpet will be covering the deck so I may skip the last layer if it is not too rough. My plan for the last layer, whatever material it winds up being, will be to use a finish resin. Well, wait, will I have to sand that before I glue the carpet in or can I just continue to use the laminating resin? Im just worried about a glue bond to tacky resin (carpet glue or PL for the deck bonding). How long before this stuff is tack free?

Woodonglass · Jun 10, 2011

Re: Is a waxed topcoat NEEDED for a laminating resin?

Whoa!!!! 24oz woven roving is NOT needed on your deck. At the most 1708 biaxial cloth could be used. I like to use it but some people just use 3 layers of 1.5oz csm and call it good. If you use Wax in your final coat of resin then you will NOT have to sand to lay your carpet. If NO WAX then the resin will stay tacky for a while but in a couple of days a light sanding will take care of that.

Yacht Dr. · Jun 11, 2011

Re: Is a waxed topcoat NEEDED for a laminating resin?

Mebbe its just me..but I always prefer to scuff before I glue carpet down.

For the rest of the project..again I prefer to wax All of my final surfaced resin/gel coatings to be sure of Full cure.

The only time I ( sometimes ) dont use wax is in small gel repairs where custom matching is playing an issue. I will just wipe off that top uncured layer with acetone before wet sanding and buffing..

YD.

HopinImFloatin · Jun 11, 2011

Re: Is a waxed topcoat NEEDED for a laminating resin?

Well, now im worried. Is the roving just overkill or will it be BAD to use it? My local boat guy said it was what he uses all the time. I was also planning on using it for the stringer tabbing along with mat and i can see that it matches what the factory had in there. I dont remember what the old deck was, long since threw it away but the remaining lip left at the hull is nearly an eight inch thick. I will try to post a pic because im not even sure its 24 oz, he just calls it heavy roving.

HopinImFloatin · Jun 11, 2011

Re: Is a waxed topcoat NEEDED for a laminating resin?

well, pic didnt work, ill have to look into that but right now i need to get back to the boat

Woodonglass · Jun 11, 2011

Re: Is a waxed topcoat NEEDED for a laminating resin?

Your pic did not work. Use the IMG link to post your pic. You can use The roving but it is HARD to wrap oever stringers etc... the Biax is a LOT easier to use especially if you have never glassed before.

HopinImFloatin · Jun 11, 2011

Re: Is a waxed topcoat NEEDED for a laminating resin?

so...will I be doing any harm if i use it in the top deck? Its already paid for and in my garage

Other than being rougher than it needs to be what should be my concerns?

Woodonglass · Jun 11, 2011

Re: Is a waxed topcoat NEEDED for a laminating resin?

No concern. If you put another coat of csm over the top of it it won't be that rough at all. Just using a LOT of resin is all.

HopinImFloatin · Jun 11, 2011

Re: Is a waxed topcoat NEEDED for a laminating resin?

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HopinImFloatin · Jun 11, 2011

Re: Is a waxed topcoat NEEDED for a laminating resin?

does this look like 24oz?

Yacht Dr. · Jun 11, 2011

Re: Is a waxed topcoat NEEDED for a laminating resin?

HopinImFloatin said:
Well, now im worried. Is the roving just overkill or will it be BAD to use it? My local boat guy said it was what he uses all the time. I was also planning on using it for the stringer tabbing along with mat and i can see that it matches what the factory had in there. I dont remember what the old deck was, long since threw it away but the remaining lip left at the hull is nearly an eight inch thick. I will try to post a pic because im not even sure its 24 oz, he just calls it heavy roving.

No worries.. its not BAD to use..its how boats were built for Years and years..

Your local is probably an old school guy that uses a variety of products and still uses 24 or 17 oz woving instead of 17 oz 1708.

For your stringer tabbing you would use 2 layers of 1.5 oz mat..woving..mat..woving...mat mat..

Or you can end with woving and "sheath" off a few strands from all the edges of the woving and "align" them to your existing woving pattern .. thats what us pros do to "hide" existing repairs from the inside ( basically blend the inside as well as the outside looking like Nothing ever happened )....

YD.

HopinImFloatin · Jun 11, 2011

Re: Is a waxed topcoat NEEDED for a laminating resin?

Thanks, he is kind of an old school guy, didnt even know what 1708 was when I mentioned it to him but he is a really nice guy. Seems to know whats going on. Ill dive in and give this a try and see what happens, best way to learn i guess. Thanks for all the help with this. Maybe ill post some pics if it comes out ok

Cadwelder · Jun 11, 2011

Re: Is a waxed topcoat NEEDED for a laminating resin?

HopinImFloatin said:
Thanks, he is kind of an old school guy, didnt even know what 1708 was when I mentioned it to him but he is a really nice guy. Seems to know whats going on. Ill dive in and give this a try and see what happens, best way to learn i guess. Thanks for all the help with this. Maybe ill post some pics if it comes out ok

Like YD said nothing wrong with the woven and nothing wrong with being old school. I've used tons of woven roving....only changed over to 1708 about 3 or 4 years ago. The 1708 is really easy to work with after using woven.

I've heard the term "heavy woven" plenty of times. I too know an old fibeglass guy that swears by the woven in lieu of 1708.....again its what he knows and has had success with. There are many types of fabrics out there and just because one guys uses this and another that doens't mean the end results aren't good.

Using woven to top off with to match the old surface is a neat trick to hide repairs...done it several times even though I'm not trying to impress anyone, just looks good. I've even seen woven used to tab in a deck with nothing else, not matt at all....not the right way, but it lasted for years and years... So the bottom line is, use what you're comfortable with, just get a good even layup, well rolled, with no air pockets and you'll be fine.

HopinImFloatin · Jun 20, 2011

Re: Is a waxed topcoat NEEDED for a laminating resin?

OK, next question, surely not the last, is it better to use "peanut butter" to help bond the floor down( with the aid of a few ss screws) or pl adhesive. Also, if pb is used, im seeing on the fiberlass supply sites that cabosil and the like are only for epoxy resins. If I go the pb route, I would also like to use it for the fillets but have seen on this site that poly will not bond well to epoxy and im using poly resin for the rest of the boat. I have been watching friscoboaters latest rebuild and when he shows how to make the pb, I believe he is using poly looking at the bottle of hardener, am i incorrect? If I make the pb with poly resin will it still be a bonding agent for the floor? Am I overthinking this?

Woodonglass · Jun 20, 2011

Re: Is a waxed topcoat NEEDED for a laminating resin?

I assume you are using Polyester Resin. You can use cabosil in both Poly and Epoxy. When making Filleting material you add chopped fiberglass fibers for added strength. Poly does NOT bond to Epoxied surfaces. Friscoboater used poly exclusively for his build. Poly will be an adequate bonding agent and yes I think you are overthinking this just a bit. It is NOT brain surgery. Just follow the examples shown and talked about here on the forum and you'll be just fine.

HopinImFloatin · Jul 6, 2011

Re: Is a waxed topcoat NEEDED for a laminating resin?

making progress. stringers are in, first layer of mat, second layer of roving then lastly covered by mat again. Was more than was done by the factory and seems very sturdy. My question is do the stringers need to be capped for structural purposes or is it just a waterproofing measure? My layup covers nearly all the way up the new stringers and all the new wood was soaked well in resin before install. Is just coating the tops with resin acceptable? Most of the wood under the deck wasnt resined or covered on the undersides from the factory. I will be gluing the deck down with pl which will cover the tops anyway. I just want to know if this is a structural thing or just a waterproofing thing. I dont anticipate this boat being a long time keeper due to the fact it is omc but 5 or so years would be nice. After all, its taken all these years to reach the point its at (its an 87)

ondarvr · Jul 6, 2011

Re: Is a waxed topcoat NEEDED for a laminating resin?

Polyester resin alone is not going to last all that long as a water barrier, you need to use glass with it or it will crack and peel off the wood. You should glass over the top of the stringers, it adds a great deal of strength and keeps water away.

HopinImFloatin · Jul 6, 2011

Re: Is a waxed topcoat NEEDED for a laminating resin?

thanks, will do then. One layer of mat enough?

Is a waxed topcoat NEEDED for a laminating resin?

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