The difference between Gelcoat and Flowcoat

[Jokani]

I have a tin of both Gelcoat and Flowcoat, purchased with the intention of completing a fibreglass repair (removed instrument panel, filled in with car filler).

I thought it was a case that Gelcoat was the base layer and that Flowcoat would be the top layer.

I have queried this with the supplier who has said that Flowcoat is used when you want a tack-free finish, and that Gelcoat remains tacky when it’s cured.

So I think for my project I juest need to brush on 1 or 2 coats of Flowcoat and then polish back to a smooth finish.

But I'm curious, for what applications would Gelcoat be used? I can't think of a scenario where anyone would want tacky Gelcoat?

 

[VicS]

My understanding is that gelcoat is what is applied to the mould and on which subsequent layers or glass and resin are built up.

Flow Coat is formulated as a final coat that can be applied on top of layers or glass and resin. AFAIK it hasa wax solution already added to it which seals the surface to prevent the tacky finish that plain gelcoat will have

 

[nigelmercier]

For the reasons Vic states, before you add a second coat of Flowcoat (Topcoat) you need to sand and degrease.

 

[rob2]

I stand to be corrected - nomenclature may be differently used in various contexts. My understanding is that gelcoat is the outer layer when laying up in a mould. Used this way, it cures completely as the air is excluded by the mould. Flowcoat is a variation of gelcoat and used to overcoat a moulding in free air (used like paint). It has wax-in-styrene added to the mix which migrates to the surface, thus excluding air and allowing a complete cure. It is necessary to wash off the wax between coats or if you intend to paint over it.

Rob.

 

[VicS]

For the reasons Vic states, before you add a second coat of Flowcoat (Topcoat) you need to sand and degrease.

presumably if you were applying multiple top coats you could use gel coat initially andthen either flowcoat, or gelcoat with 2% added wax solution, for the final tack free finish

 

[prv]

presumably if you were applying multiple top coats you could use gel coat initially andthen either flowcoat, or gelcoat with 2% added wax solution, for the final tack free finish

Exactly.

I never buy flowcoat, just have a tin of gelcoat and a can of wax solution, and add it when a particular coat will be the final one and not covered by a mould, film, etc.

Pete

 

[fisherman]

Before we could buy flocoat we mixed layup resin with 20% gelcoat, I think.

 

[Mrnotming]

I stand to be corrected - nomenclature may be differently used in various contexts. My understanding is that gelcoat is the outer layer when laying up in a mould. Used this way, it cures completely as the air is excluded by the mould. Flowcoat is a variation of gelcoat and used to overcoat a moulding in free air (used like paint). It has wax-in-styrene added to the mix which migrates to the surface, thus excluding air and allowing a complete cure. It is necessary to wash off the wax between coats or if you intend to paint over it.

Rob.

+1 (SWMBO flowcoated our 9' Rana punt many moons ago, it was described as waxcoat then!

 

[Tradewinds]

Handy video by East Coast Fibreglass on their website - deals with Gelcoat & Flowcoat among other things.

 

[coopec]

Garry

You must be finishing off your project Repairing gelcoat after multiple instrument removal?
Can we see a pic of the finished job: any chance?

Clive

 

[coopec]

Garry

You must be finishing off your project Repairing gelcoat after multiple instrument removal?
Can we see a pic of the finished job: any chance?

Clive

 

[Jokani]

Hi Clive, I certainly will.