Been looking into resins a little more....

[gazza2006au]

I was a all epoxy guy but i only just noticed how easy polyester and vinyl ester resins soak into the cloth and it had me thinking about changing over, Will vinyl ester resin from the same shop i bought epoxy resin from stick? vinyl over the top of epoxy

can't seriously see my self wetting out 40 square meters of cloth using epoxy resin in the middle of winter i would barely make it 5 square meters of the constant massaging of the resin to absorb into the cloth

vinyl ester on chopped mat and cloth soaks in like water on tissue i had no idea untill i just researched it

when i done my transom last year it would take a good 40mins using epoxy resin to saturate 2 square meters of cloth using a 100mm roller, i could easily do that 2 square meters in 10mins using vinyl ester resin theway it soaks into the cloth almost instantly

whats your opinions am i stuck with epoxy and the long wetting out process or will vinyl ester work?

[tug_tellum]

Gaza, I wouldnt risk it. We always worked on the theory that you can put epoxy over polyester (or any other ester )but not the other way around. Now I know some of you guys have put polyester flowcoat over epoxy but I dont know how long that will last for. I cant understand why guys want to repair a polyester boat with epoxy thats usually 4 times more expensive than polyester and 4 times harder to work with when the boat is x amount of years old and will last another x amount. of years.if refurbished with polyester
Some of the ways you guys do things is good if your boat is going to be a family heirloom but there is no guarantee that your great great grand son will want this old , prehistoric boat when since those days ,the wheel has been reinvented and there are much newer and flasher boats on the water.
But its up to you. Undoubtedly someone out there will tell me how wrong I am and they can do this and that but when you look at it ,Its not parent material and will move differently in expansion and contraction as well as flex.
My opinion only. Its really up to you,but you wouldnt be asking the question if you didnt already have doubts. Cheers. Tug Tellum

[EdBerg]

Gazza, as far as I know vinylester or polyester resins cannot be applied on something that has been laminated with epoxy, it won't stick to it. Epoxy will stick on top of the first two but not the other way around.

[gazza2006au]

Thanks Tell and Ed, I used epoxy because i wanted the strength of it to be super strong but the wetting out of the epoxy takes so long the repetitive rolling over and over the same spot to get it translucent is a long job i was using a 100mm roller and i think around 250mls of resin and by the time i finished the resin it was heating up

the guys using poly or vinyl are mixing up 800mls 1000mls at a time because it wets out so easy that is crazy i wish i could mix up 1000mls of epoxy without it going off

jumping in an out of the boat mixing 250mls all day long is going to be tiring, i guess i have to finish it with epoxy now bugger i really should have researched vinyl at the beginning as from what i understand vinyl ester resin is thinned epoxy resin, when i researched resin's i only looked at poly and epoxy

[EdBerg]

If you are having trouble wetting out with epoxy, chances are that your using the wrong fiberglass mat/cloth, the binder which is used on the glass strands for poly/vinylester resin doesn't dissolve easily/at all when epoxy is applied to it. It may pay you to talk to one or more large Fiberglass suppliers for expert advice. Another thing is, are you heat curing your epoxy after it sets as well?

[gazza2006au]

Ed i was using double bias from the same shop i bought the resin, With epoxy cold weather doesn't effect it curing just the colder it is the longer it takes to cure, Epoxy is much thicker in viscosity than poly and vinylester i take it

I'm just going to have to roll with it

[EdBerg]

The heating post cure is to make it stronger, same with Poly/Vinyl ester resins. The post curing heat just helps to complete the chemical reaction. I think off the top of my head it is about 50-60C. Do not apply the heat whilst it is curing or you will cause an overheating reaction. When I was much, much younger I worked at a boat building company (Savage) and they had a very large heated insulated room that the boats in their molds would sit in for a while once the resin had hardened up and cooled. They would then be wheeled in to heat up before they would be taken out of the molds. I wasn't involved in that side of things but from what I remember it was to gain additional strength and cure the resin completely.

[EdBerg]

After I posted the above bit I was giving it a bit more thought regarding your trouble with the epoxy absorption, so going to ask you an obvious dumb question so please don't get offended:

Are you using a fiberglass roller to roll out the glass after you wet out the cloth with a paint roller/brush/scraper?

[chris69]

Gazza what weight cloth are you using 300 gram 450gram 600gram the heavier the cloth the harder it is to wet out, and what ratio epoxy are you using 2to1 4to1 5to1 ,5to1 epoxy wets out 450gram DB real well.

And use a 4inch brush don't use a roller it can't hold enough epoxy to wet out your DB cloth and use the brush to push the epoxy into the cloth.

[gazza2006au]

After I posted the above bit I was giving it a bit more thought regarding your trouble with the epoxy absorption, so going to ask you an obvious dumb question so please don't get offended:

Are you using a fiberglass roller to roll out the glass after you wet out the cloth with a paint roller/brush/scraper?

im using mohair rollers mate

[gazza2006au]

Gazza what weight cloth are you using 300 gram 450gram 600gram the heavier the cloth the harder it is to wet out, and what ratio epoxy are you using 2to1 4to1 5to1 ,5to1 epoxy wets out 450gram DB real well.

And use a 4inch brush don't use a roller it can't hold enough epoxy to wet out your DB cloth and use the brush to push the epoxy into the cloth.

400g and 450g is what i will be using and have used plus 800g all double bias, epoxy is 5:1 the whole problem is getting the cloth to go translucent it just takes forever i am constantly rolling the resin into the cloth its like it cant absorb it and takes 15-20mins to soak in but my resin starts to gel around that time to as the resin heats up

The cloth and resin is from a shop just up the coast from me

Using a brush is the worse possible way in my case u get absolutely no resin on the cloth

Should i be fully dunking the roller under the resin? Mixing 250mls in a 100mm roller tray only covers about half the roller

[gazza2006au]

Forgot to add when i was glassing my transom i had to wet out a rather large area and keep going back to the start to message the resin into the cloth and this would repeat over the whole area to be glassed

[Cox76y]

Gazza, use the mohair roller for your first hot coat. Place your double bi on top. Then totally saturate the roller with resin and just throw it on. If the surface is flat I'll poor it on and spread it with the roller. Don't be scared to apply a thick layer. The thicker the better s any excess will be absorbed by my next layer. Once you have completed a few minutes the binders in the matt should be breaking down and becoming translucent.. Any spots that aren't, apply more resin to. Then get a proper fibreglass roller and go over to push all the air out. Only use the mohair roller to get the resin onto the cloth and quickly spread over it.. Can't stress enough though, you can't be too scared to just throw it on there quick n thick.. That's how I do it anyway.. Another dumb question, you are applying a liberal amount before you lay the glass, not just a thin layer?? Also, the choppy will be much easier to wet out than the double bi. You don't need to use double bi for every layer..

[EdBerg]

So that is why you are having your problem of wetting out.

Coat the area you are working with epoxy with the mohair roller, add the glass, use the mohair roller to wet it out and then use a fiberglass roller to remove the air then add additional layer/s of glass and wet out with a bit less epoxy and work it with the fiberglass rollers. The excess resin from the lower layers will be forced to the surface ensuring that the trapped air gets removed (becomes transparent) and that the resin gets all the glass saturated properly with out excess. If you do get an area is it a bit dry then add some resin from the mohair roller over that area and again use the fiberglass rollers to work it in. For multi layers on a wooden base you would normally use matt followed by woven cloth DB/Triaxial etc.,followed by matt again. Then repeat depending on job and thickness required as well depending on the ambient temps.

You should not have any problems after that. The trick is to use just enough resin to wet it out but not have excess resin, as excess resin makes it weaker, The strength is in the glued together glass fibers and excess resin just makes it brittle and weaker.

Fiberglass rollers come in various sizes and shapes. I made a set of rollers when I started in the fiberglass business 47 years ago and still have them. Those one are simple metal all thread rods 6mm. 10mm and 13mm, cut down to 70mm and 100mm wide, a small hole drilled in the ends and thick wire bent and shaped to fit in a wooden handle and the other open ends fit into the small drilled ends. I also bought ally paddle rollers of various widths that are about 25-30mm thick and up to 200mm wide. These have horizontal slits in them and are great for doing large areas with multiple layers of glass in one hit, but they throw the droplets of resin every where which if you are laminating large areas isn't a problem and then finish off with the smaller threaded rollers for a neat surface finish.

There are various type and here are some samples.

https://www.ebay.com/itm/3-Pcs-Paddl...gAAOSwPEtcvtkC.
https://www.fibreglast.com/product/P...lers_Squeegees
https://www.fibreglast.com/product/A...lers_Squeegees.

Just do a E-Bay search on fiberglass laminating rollers.

I could show you how to laminate if you were closer to me. Hope this helps!

[gazza2006au]

I just bought a full roll of woven roving its a bit thick 600gram this is only for stringers I'll try the pour technique might be a bit iffy with 75mm tabbing than up and over the stringers I'll see how i go with this cloth maybe it'll wet out easier

maybe the mohair rollers were the problem i have been searching and they may not be applying enough resin, i will keep searching to try find some dedicated resin rollers i know West System does rollers but $10 for 2 not cheap when your doing a whole boat and they'll be no good after about 30mins to 1hr each roller