Composite layup information - Gelcoat and Epoxy

[martno1fan]

Hi thanks,the glass cloth i use usually is biaxial cloth which is 600g folowed by 200g carbon twill.On the one in the pics id ran out of the 600g so used 450g and two layers of carbon so its possible the next one will be a tad lighter.Most people seem to just want the carbon in the rear 3rd but this ones for show and go.Im finding these layups work well and im not having issues with curing times but then even in our summers its not as warm as you probably get.On the standard glass hulls i use 350-450 mat first depending on customers needs then the cloth on top,seems to make a nice stiff hull.The biaxial cloths are stronger than twill cloths and drape very well as they have stiching running through them but they arent as smooth to the touch as twills,you need to be carefull how you pick it up as it will actually stretch lol.If you havent used them give them a go and theyre actually cheaper than a twill cloth.
Nice looking work on the cat,any pics of the finished hull.Id love to build a large cat sometime its just finding the time for the plug and moulds lol.Allready have a new vee on the go based on the Apache bottom (new top will be layed next week), and planning a 70" cigarette next along with a tunnel hull lol.I think i need abigger workshop and 3 pairs of hands lol.
Mart
Heres a link to some if you havent seen any before.

http://cgi.ebay.co.uk/Biaxial-Cloth-600g-m-1-27m-wide-/360291679904?pt=UK_CarsParts_Vehicles_BoatEquipment_Accessories_SM&hash=item53e30ebea0

[DISAR]

Many thanks!

[befu]

I was also told by Fiberglast not to thin it. That was from their techline, I think the guys name was Mike.

yeah, I remember you saying that before and they say it on the website also, but sometime you just have to try. It is basically epoxy with additives. Also, most of the epoxies out there are manufactured at one of only a few manufacturing facilities from what I understand. so maybe, if you use an epoxy with the same base as what the surface coat is, it might work. But if you use a different one, it won't? So they have to say do not do it.

Well, being one of those engineers, I just had to try it. that and I new I was destroying the layup anyways. You saw the video, seemed to work. Now, if they say you might be able to try it and someone scraps out a $20,000 project, that might be grounds for a lawsuit, or bad business at the best. So they play it safe and say "don't try it". They are a reseller, not a chemical blender I would guess.

anyways, I think I am going to try a small boat hull and thin the surface coat by 10% this time. We will see. Another epoxy might not work at all, who knows. It will also make it weaker I would think, but that is because you are thinning the additives, but the lose may not matter to me (uv protection would be one).

Brian

[befu]

Hey Mart, thanks for the links, will watch for them to be back up and readup on it.

Disar. I also have tried the sanding after curing and it seems to work pretty good usually. Just a lot of work to do. i would rather just use the epoxy. maybe the shortcuts just won't work out in my application, I do not know.

I also prefer the polyester resins for there ease of use and really good adhesion to later layers due to the uncured resin layer. The epoxies are nice to be able to use in the house in the cold winters. Otherwise I have to wait for summer or do it all at work, which then takes time away from home and restricts when I can do layups so I do not fume out work!

Thanks for sharing guys,

Brian

[DISAR]

So what is your conclusion on applying epoxy on top of polyester gel coat? Possible? best way to do it? Thanks