Gelcoat/flowcoat/topcoat possible problems

[Solent Bombard]

Quick question if I may could not find a specific answer in searches so here goes

I'm currently sanding/abrading my deck for flowcoat orange on the sides and main deck in grey non slip flowcoat.

With the abrading I have gone through to the matting in places where the gelcoat was thin and other places I have had to do hole repairs so the colours of the deck are not uniformal.

I recieved my flowcoat from eastcoast today and did a test on a piece of jockey seat I have cut out to fit a hatch I sanded it down the same as the deck and also went through the gelcoat to the Matt in places to do a similar trial to the deck.

And one coat of rollered on flowcoat was almost see through even though it's a coloured batch.

I could see everything underneath!!!!

Is this normal or do I need to do a couple coats of coloured gelocat first to try and cover the different colours and then a final coat of flowcoat to seal it.

It almost seems I need a primer undercoat first to get the colour right.

Thanks

[A1an]

I had to put several coats on my console to get a uniform colour, I made sure I got rid of the surface wax with a good wipe down with acetone or cellulose thinners.

I also learnt that when rollering that if the coat was too thin then the wax couldn't rise to surface.

[A1an]

[paintman]

I know from my own game - vehicle paint repairs - that some colours, esp reds, are referred to as 'low hiding'. Basically means that it needs a lot of coats to completely cover what's underneath. Why that is the case I have no idea.
Wonder if this is what is happening with you?

[hamster]

Did it come with the pigment in it or have you added it?

Rollering will put in a really thin coat so will need a few layers of gel before final flow coat layer. As said previously orange can be a bugger to cover with as you can see through it until you get a good covering.

May be better putting it on a bit thicker with a brush on the deck and using roller to get it evenly covered. You won't want to smooth a finish on there anyway or it'll be like an ice rink when wet even with non slip in it


RYA Instructor, Trainer, Examiner and Skipper

[Solent Bombard]

Originally Posted by hamster

Did it come with the pigment in it or have you added it?

Rollering will put in a really thin coat so will need a few layers of gel before final flow coat layer. As said previously orange can be a bugger to cover with as you can see through it until you get a good covering.

May be better putting it on a bit thicker with a brush on the deck and using roller to get it evenly covered. You won't want to smooth a finish on there anyway or it'll be like an ice rink when wet even with non slip in it


RYA Instructor, Trainer, Examiner and Skipper

Hi graham

It came with pigment in it so mixture should be correct did not realise how thin a coating it would be though.

I have some clear gelcoat so looks like I'll have to get some pigment and put down layers of that first and then do a final coat of flowcoat this is just for the orange on the sides.

With the dark grey should cover easier.

[ShinyShoe]

Gel before you flow?? Not so sure... You may not get the gel to cure. Gel like to be free from air...

You are aiming for a thicker layer than paint. I find direct rolling is too thin. So I tend to spread it on and smooth it with a roller. I would use flow and then degrease between coats if second coat needed. But unlike paint gel/flow doesn't need multiple thin coats to make one thicker coat.

No experience with orange I'm afraid..

[Nos4r2]

Originally Posted by ShinyShoe

Gel before you flow?? Not so sure... You may not get the gel to cure. Gel like to be free from air...

It'll be fine, as long as you don't try and rub it down. The next coat of gel will exclude the previous one so it cures, til the last coat with wax in will cure the surface.

[hamster]

Putting layers of gel onto each other when they are still 'tacky' on the surface to touch allows for a (all be it not fairly weak) chemical bond between the layers as well as physical bond so you get a stronger bond and less chance of cracking etc than layers of flow coat.

This is a useful characteristic when building up layers or laying up in a mold where your first layer is gel and then your laminating polyester and glass onto the back of it. If it didn't stay tacky then the gel could peel off if the physical bond was weak. Also if it wasn't a characteristic we wanted to utilise then they would add wax to it as part of the manufacturing process so it doesn't remain tacky when it dries. Oh wait that's what flow coat does, useful for your final layer where your not laying anything else on the back.

Don't be tempted to add more pigment than manufacturer recommends as it can stop the gel going off properly if you add too much or make it weaker and more likely to crack or delaminate. Go for more layers or thicker layers to hide what's below it.


RYA Instructor, Trainer, Examiner and Skipper

[C-NUMB]

I find working with gel coat and flow coat harder than any paint, tough to get a nice surface. And a thick layers is a must. What i do is working with multiple layers, first gelcoat and last flowcoat. When properly cured will sand and rub it down. Don't know how to get a smooth surface when applying it, it just wont happen for me....

On a few times had issues with flow coat spots left tacky, but "painting" those spots with the styrene wax( the stuff you mix with gelcoat to achieve flowcoat) has solved
the issue.

[Solent Bombard]

Cool cheers guys

Another query what's the best grit grade should I prepare the deck with for best adhesion.

I'm currently on 60/80 grit as the deck is so lumpy and is the only grade I can get any worthwhile work done.

Should I work to a finer grit before I apply the coats

[C-NUMB]

Originally Posted by Solent Bombard

Cool cheers guys

Another query what's the best grit grade should I prepare the deck with for best adhesion.

I'm currently on 60/80 grit as the deck is so lumpy and is the only grade I can get any worthwhile work done.

Should I work to a finer grit before I apply the coats

80 should be fine. Think 100 is the finest recommended grit, if surface is to smooth it will not stick that well.

[hamster]

As above stick with what your using as any finer and you won't get much of a key for the gel to hold on to.

[Solent Bombard]

Awesome saves me a load of sanding then

I'll stick with 60 to 80

Thanks c-umb and ham

[gtflash]

are you changing the colour? or same colour? Im toying with a colour change. Ed @ ribraff says darker colours or white go on best, red and oranges are hard work