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[destroyer42]

Dear Colleagues,
I have just finished renovating a wooden Marbelhead yacht and I was wondering if I could use the tissue fibre glass and a coloured gel coat to finish the model off. The reason for this is that I don't have to paint it.
Any advice would be appreciated.

Destroyer42

[Damien]

Never tried it but thinking on it the gel coat is somewhat thicker than resin and may not fully penetrate the tissue it might pay to use a roller to coat the hull then place the tissue on the g/coat and apply more rolled on g/coat, as long as the tissue lays flat with no wrinkles it would possible to get a finish that dosen't require sanding, as this would ruin the finish on the gel coat and leave it still needing paint.

Damien.

[Vintage]

From memory - contact with air, ie: not against a mould surface whilst curing, inhibits polyester gelcoat & causes the exposed surface to remain tacky - it's designed to do this & only fully cures when the subsequent layers of tissue / glassfibre are laid up over the surface.  I've successfully used a wax additive in the past when gelcoating areas in the interior of model hulls & this prevents it from staying tacky - can't remember the exact product but if you call a company like Bondaglass or Strand Glassfibre then I'm sure they'll be able to help.

Another point is that gelcoat is fairly brittle & you might have issues with cracking particularly if you're only using a thin fibreglass tissue - I'm actually in the process of restoring a 1930's 6 metre yacht &, knowing how the hull flexes, would have concerns....

Not sure about epoxy resins - might be worth giving a boat chandlers a call??

Mark.

[Colin Bishop]

There are resin topcoats but, as mark says they can be brittle. You may be better off with a decent marine paint susch as International Toplac or Brightside. They do give a superb finish.

http://www.boatpaint.co.uk/acatalog/International_Topcoats_Special_.html

Colin

[Circlip]

The Gel coat is normally a finish coat laid INSIDE a mold which then has sucessive layers of cloth/mat/tissue or whatever intersperced with polyester resin. Colour pigments can be mixed in with the Gel coat to give a gloss, coloured finish. In the event of not having any specific Gel coat resin, Pregel Paste can be mixed with the normal polyester lay up resin which gives a Thixotropic mix. If you have to "Repair" a Gel coat, as Mark (Vintage) has stated, the surface stays sticky for a long time UNLESS you "Seal" the coat with clingfilm to let it go orft (Excludes the air).

  Polyester type resins tend to be more brittle than Epoxys but you need to heed the warnings of reaction to the different chemicals on the human operators at the toy manufacturing stage.

  Don't know of the "New" suppliers, but Strand Glass always filled my needs when trying to get stuck up, molding Fugesalges for toy gliders

  Regards  Ian.

[wbeedie]

Two pot paint is way to go not cheap but uses a hardener similar to resin and as for gelcoat had no problems when fathher in law built a hull fro marine ply and glassed then a gel coat finish mind you a hot summer that year

[martno1fan]

You can just use poly resin with any gelcoat pigment to get the colour you want  as said dont use gelcoat .There are additives you can add to gelcoat to make it cure outside a mould in the air but id stick to using resin wether poly or epoxy.You only need a very little amount of pigment to get the colour you want,works great i use it all the time building my hulls.As said gelcoat wont cure in the open air it stays tacky which is whats its meant to do so when you add resin and cloth or mat into your gelcoated mould etc it gets a good hold which it wouldnt if the gel had gone hard  .
Mart
http://www.ecfibreglasssupplies.co.uk/category/tabid/60/entityname/category/categoryid/458/sename/pu-foam-board/tabid/60/c-604-polyester-epoxy-colour-pigments.aspx

[Bradley]

What about using a tough, hard setting floor varnish with a woven fibreglass tissue which, I believe, is what some of the model aircraft guys use for wing skinning.  Can't remember the make of floor varnish but it was one of the diy ones and I remember seeing it in Homebase and B&Q.  Hope this helps. 

Derek.