Covering naked fibreglass

[bbdave]

I have made an outboard well and now have an area of naked fibres can i just cover with west epoxy then painted?

Dave

 

[Quandary]

You can mix some of your epoxy with filler, glass bubbles is by far the easiest to fair, then paint it. Alternatively you can brush on polyester flow coat which is gel coat with a wax additive which goes on (and runs) like paint. It is much harder to fair if the surface is uneven so the epoxy filler is perhaps the best way, but flowcoat gives a good finish over flat surfaces like plywood. All the internal bilge compartments, hidden locker lids, areas under berths and bilges in our boat are flowcoated and I can attest that it is durable, smooth and easily cleaned.
If you do not already have the epoxy it is probably better to buy a two pack filler like Hempel Unifiller (or Profiller for a very big job) or International Interfill but all epoxy based products tend to be expensive.

 

[prv]

You could, but personally I wouldn't waste the money on epoxy (assuming the structure is already strong enough).

Get some gelcoat (and catalyst) and a small bottle of "wax in styrene". Mix it all up according to the instructions and apply like a thick layer of paint. Do multiple layers (once each one has gone off) if needed to cover the fibres. No further finish required. It won't look quite as smooth and perfect as gelcoat that's been laid up in a mould, but good enough for an outboard well and you're unlikely to do better by any other method. Gelcoat is much cheaper than epoxy. You could also buy flowcoat which is basically the same gelcoat with the wax already added for you.

Pete

 

[oldsaltoz]

Just a reminder, Epoxy will stick to almost anything and form a good bond, however not much will stick well on epoxy.

If you need to coat an Epoxy surface then use an epoxy primer and apply what ever you like within reason.

Good luck and fair winds.

 

[William_H]

Epoxy

Just remember epoxy will deteriorate in sunshine UV unless covered with a paint of some sort (not epoxy)
Polyester flow coat is made for the job. olewill

 

[penfold]

You could, but personally I wouldn't waste the money on epoxy (assuming the structure is already strong enough).

Get some gelcoat (and catalyst) and a small bottle of "wax in styrene". Mix it all up according to the instructions and apply like a thick layer of paint. Do multiple layers (once each one has gone off) if needed to cover the fibres. No further finish required. It won't look quite as smooth and perfect as gelcoat that's been laid up in a mould, but good enough for an outboard well and you're unlikely to do better by any other method. Gelcoat is much cheaper than epoxy. You could also buy flowcoat which is basically the same gelcoat with the wax already added for you.

Pete

Can you do multiple layers of flowcoat? I thought you had to shift the wax before you could put anything on top?

 

[satsuma]

You could, but personally I wouldn't waste the money on epoxy (assuming the structure is already strong enough).

Get some gelcoat (and catalyst) and a small bottle of "wax in styrene". Mix it all up according to the instructions and apply like a thick layer of paint. Do multiple layers (once each one has gone off) if needed to cover the fibres. No further finish required. It won't look quite as smooth and perfect as gelcoat that's been laid up in a mould, but good enough for an outboard well and you're unlikely to do better by any other method. Gelcoat is much cheaper than epoxy. You could also buy flowcoat which is basically the same gelcoat with the wax already added for you.

Pete

Just add the wax to the very last coat only! The prevıous layer/s without wax will remain "tacky", and allow another layer to bond. The wax floats to the surface and makes sure the last layer goes off!

 

[snowleopard]

Flow coat will do the job but the finish won't look professional so I'd avoid it in an area that is visible. It will tend to look as though you have slapped on paint too thick. It works fine in bilges etc where it is on a fairly horizontal surface and can't run or 'curtain'.

In those circumstances I would use laminating resin mixed with 'Fillite' powder. It can either be mixed to honey consistency and brushed on or putty consistency and trowelled. It will give a surface that can be sanded to any level of finish you like using power sanders - I use an angle grinder to remove the surface film, then a belt sander to flatten and finally an orbital (round or rectangular) for final finishing. It is then ready to paint.

Whatever coating you use, abrade thoroughly before applying.

 

[electrosys]

I have made an outboard well and now have an area of naked fibres can i just cover with west epoxy then painted?

Dave

Well - I don't understand the question ... (not enough info)

Is this "area of naked fibres" already attached/ glued in place (part of the original structure perhaps) ? If so, then applying some paint is all that's required. If the surface isn't smooth enough to take paint, then a layer of epoxy resin or polyester resin, rubbed down to an acceptable level of smoothness is all that's required, before painting. If the surface is really rough, then use well-thinned putty.

The only exception to this is if the "area of naked fibres" is in an underwater location (which I suspect it might be), in which case a layer or two of epoxy resin would be my recommendation, before applying any surface finish. 2-part epoxy paint would be the ideal paint to use if you have some handy.

 

[late-night-lochin]

Just add the wax to the very last coat only! The prevıous layer/s without wax will remain "tacky", and allow another layer to bond. The wax floats to the surface and makes sure the last layer goes off!

Absolutely correct! If you add wax in styrene to intermediate coats, they won't bond.

A good wipe with acetone prior to recoating will remove any dirt from the surface which naturaly comes out of the atmosphere.

 

[bbdave]

The area in question is where the original airtight box was moulded into the hull i have cut the top off to form the well but as the area wasn't acessed for the original flowcoat the bottom of my well has bare fg so i want to protect this from sea water.

I'm not bothered to much about looks and strength isn't an issue, i have some west epoxy left from making the well walls so i may just thicken that and apply it