Model Boat Mayhem

Technical, Techniques, Hints, and Tips => Painting, Finishing and Care. => Topic started by: tbone on August 08, 2010, 09:00:34 am

Title: fibreglass resin vs epoxy resin
Post by: tbone on August 08, 2010, 09:00:34 am
I've got a boat built of wood that I will need to sand, seal and paint. 
I planned to coat it with resin to seal and strengthen it, sand it and then paint it.
I also planned to coat the inside with resin also to seal and help strengthen it.

Epoxy resin is 3 times the cost of fibreglass resin.  Epoxy resin is hard to find while the fibreglass resin is readily available.
The salesman where I found the epoxy resin said that it requires special primer if it's to be painted over and it costs more than the epoxy resin itself!
I know people who coated their boats with fibreglass resin years ago and it worked well from what I can remember.

Any advice would be great.

Also what is this sanding I hear about?  Like automotive sanding primer?

Thanks,
Tbone
Title: Re: fibreglass resin vs epoxy resin
Post by: Prophet on August 08, 2010, 09:36:19 am
I used to use the fiberglass repair kit from halfords ( for tugs...since they were around 600mm) around £19 i never primed my wooded hulls instead.. i added 1 coat of pure resin with a paint brush,(try not to leave big runs nice thin coat)  the wood soaks most of thats in, give it a good rub down with 80 grit , then added the matting with the resin (all smoothed in with a credit card size bit of plastic card) once its dried sanded it with 80 grit then added a further 2 coats of pure resin. and then sand smooth starting at 80 grit working to 600 then up to 1200!

i dont doubt that you may need a primer for some resin uses but on wood i doubt its even worth thiking about as wood is absorbent.

try here for GRP products that i use (slow drying)

http://www.fiberglasssupplies.co.uk/acatalog/resin_kits.html (http://www.fiberglasssupplies.co.uk/acatalog/resin_kits.html)

also try here i am lead to belive there products are easier to use

http://www.westsystem.com/ss/ (http://www.westsystem.com/ss/)

Title: Re: fibreglass resin vs epoxy resin
Post by: Arrow5 on August 08, 2010, 11:38:36 am
Prophet, have you noticed that Tbone is in Canada.     Tbone, do you mean sanding sealer ?  Check local model aircraft shop, it is a sealer for balsa wood that isnt required when fibre-glassing.  Fibreglass resin from auto body-shop is usually polyester as opposed to epoxy. Price difference same in UK, polyester is OK for most jobs, smell is awful and dangerous so well ventilated workshop. I`m sure there is a "how-to-do-it" on here somewhere.
Title: Re: fibreglass resin vs epoxy resin
Post by: mike_victoriabc on August 08, 2010, 03:38:02 pm
You're in Langley - wander into IPP there and harass Mark & Blair (their uncle has a Shelly Foss tug - they built a case for it) and ask them - they should be able to help you. The two local groups have fellows that have gone through those adventures and can help as well.
regards, mike
Title: Re: fibreglass resin vs epoxy resin
Post by: tbone on August 08, 2010, 06:33:37 pm
Thanks guys.
The stuff most places carry is 3M brand fibreglass resin.  There is a marine supply store that carries West System products but the price is much more.
Mike, never thought of IPP, I'll try and check with them next week.

Tbone
Title: Re: fibreglass resin vs epoxy resin
Post by: Perkasaman2 on August 08, 2010, 09:50:50 pm
Model aircraft builders use 0.6 oz/sq. yd tissue with  laminating/coating epoxy resin for finishing their models and these materials are also ideal for sealing/finishing model boat hulls. They should be fairly find.  :-)
Title: Re: fibreglass resin vs epoxy resin
Post by: CGAux26 on August 09, 2010, 01:17:51 am
Perkasaman, can you clarify what you mean by "tissue?"  Is that like the old silkspan paper we used back in the '60's to cover airplane wings?  Or what?
Title: Re: fibreglass resin vs epoxy resin
Post by: Peter Fitness on August 09, 2010, 07:11:36 am
I coat all my wooden hulls with fibreglass resin, inside and out. It can clog sandpaper, but you just need to go slowly.

Peter.
Title: Re: fibreglass resin vs epoxy resin
Post by: tbone on August 09, 2010, 08:20:21 am
Thanks for the feedback.  I suppose I'm getting a bit ahead of myself as I'm still getting the hull together.  It's my first attempt at a scratch build so will definitely need some filling and sanding.  Someone told me to sand it down, coat it with resin, sand and then use autobody filler on the fibreglass to smooth it out and do my filling.  Is this correct or should I use wood filler, sand it down and then coat it with resin?

I do understand that after the resin the autobody filler would be used to smooth out imperfections but I'm referring to the major filling and corners and wood joint/gaps.

Tbone
Title: Re: fibreglass resin vs epoxy resin
Post by: Perkasaman2 on August 09, 2010, 11:00:00 am
Hi CGAux26,

http://www.ripmax.com/item.asp?itemid=S-FG6&Category=T0410                               ;)
Title: Re: fibreglass resin vs epoxy resin
Post by: Bob_V on August 09, 2010, 11:44:37 am
tbone,

Try here http://www.fibretechgb.com/index.html

Just used their finishing resin to coat my model of a Chris-Craft mohogany Runabout.

Gave me an excellent finish and is based in the UK.

Bob.
Title: Re: fibreglass resin vs epoxy resin
Post by: Peter Fitness on August 09, 2010, 11:53:37 pm
I use body filler for major gaps, corners etc, but wood filler on the outside of the hull prior to application of a resin coat. The resin strengthens to wood filler, as well as the wood itself.

Peter.
Title: Re: fibreglass resin vs epoxy resin
Post by: tbone on August 10, 2010, 01:43:31 am
Thanks Peter.  I'll try body filler for some gaps corners I've got before I coat the hull with resin. 
Tbone