Brush on fill coats?

[Alan Gage]

Never tried it before. Always seemed like a lot of slow and sloppy work. But this morning I thought I'd give it a shot and I think I'm pretty happy with it. Went on pretty quick and I think I got a more consistent thickness than with the roller. Plus I didn't have to worry about getting rid of all those bubbles the roller introduces. Really nice looking finish so far. Had to switch to a new foam brush at the halfway point (16.5' tandem).

Anyone else tried it?

Alan

 

[pblanc]

I use disposable foam brushes to apply fill coats of epoxy all the time.

 

[Muskrat]

Slowing it down can be a good thing. Brushing it on gives the fabric a nice amount of time to slowly absorb resin, especially kevlar which seems to take longer to soak it up. On smaller projects I find myself not using a brush or roller at all and just using my gloved hand to spread it out and squeege the excess.

 

[Jim Dodd]

If I'm wanting to lay on a heavy fill coat, on a surface that's still tacky, which is the way I do it, I'll go with a roller, and maybe tip with a brush.

A foam brush on a dry surface, needing only a thin coat, a brush is fine. Slower, but appropriate, as you can control runs better.

 

[Guest]

Never tried it before. Always seemed like a lot of slow and sloppy work. But this morning I thought I'd give it a shot and I think I'm pretty happy with it. Went on pretty quick and I think I got a more consistent thickness than with the roller. Plus I didn't have to worry about getting rid of all those bubbles the roller introduces. Really nice looking finish so far.

Alan, fill coating a whole boat?

I can’t imagine. I have much better success rolling out a hull bottom and going back to tip out the bubbles with a brush, even if I have to roll out an additional coat. Well, half a bottom, sheerline to keel line, tip that out and then move on to the other side and overlap a bit.

I top fill smaller patch areas with a brush, but that is mostly because I am too cheap to expend a foam roller for a small area.

My brush loading and application technique is terrible compared to my roller work, despite working briefly as a commercial painter. That may explain the “briefly”, but god bless foam rollers for consistent even coats.

Had to switch to a new foam brush at the halfway point (16.5' tandem).

That is the reason I lay out a spare roller or foam brush before starting any large resin job. It sucks to have a roller or brush fall apart mid-job and discover that the shop stock doesn’t contain a spare.

One that topic, those of you who quickly run through disposable brushes and rollers, what is a good source for brushes and rollers purchased in quantity?

 

[Alan Gage]

Yes, whole boat. I did the second coat last night and it went good too. Lately I've been having trouble with both the larger black foam rollers (that I get locally at the hardware store) and the little white cigar rollers (from RAKA and Express Composites) falling apart on me so I thought I'd just try a brush since I waste one tipping out the roller coat anyway.

Seems like by the time I roll out the entire coat and then go back to tip it out with a dry foam brush that the epoxy has setup just enough to resist the brush smoothing out all the inconsistencies. Or else it can no longer self level to fill in all the strokes or chatter marks from the brush.

With the roller I have a hard time leveling out heavy areas. The brush seemed to do better at this. Not much technique to it. Just brush back and forth and up and down to spread it around. It's a lot thicker than paint or varnish and takes more elbow grease to spread it by brush. I don't know how well it would work in the winter time with 65-70 degree shop temps as opposed to yesterday at 80 degrees.

Alan

 

[Jim Dodd]

Yes, whole boat. I did the second coat last night and it went good too. Lately I've been having trouble with both the larger black foam rollers (that I get locally at the hardware store) and the little white cigar rollers (from RAKA and Express Composites) falling apart on me so I thought I'd just try a brush since I waste one tipping out the roller coat anyway.

Seems like by the time I roll out the entire coat and then go back to tip it out with a dry foam brush that the epoxy has setup just enough to resist the brush smoothing out all the inconsistencies. Or else it can no longer self level to fill in all the strokes or chatter marks from the brush.

With the roller I have a hard time leveling out heavy areas. The brush seemed to do better at this. Not much technique to it. Just brush back and forth and up and down to spread it around. It's a lot thicker than paint or varnish and takes more elbow grease to spread it by brush. I don't know how well it would work in the winter time with 65-70 degree shop temps as opposed to yesterday at 80 degrees.

Alan

How long did you wait between coats ! Going over the dry surface with a brush is duifferent than tacky .
Were you using RAKA 350 non- blush hardener when you experience the foam break down ?

 

[Alan Gage]

How long did you wait between coats ! Going over the dry surface with a brush is duifferent than tacky .

I can imagine it would be. I waited about 24 hours so it was hard.

Were you using RAKA 350 non- blush hardener when you experience the foam break down ?

Surprisingly, yes. Had never had a problem with RAKA resin before.

Alan

 

[Jim Dodd]

Maybe a formulation change ?

Might be worth a phone call.
They had a sale going on last Winter. Yes, I think a phone call is in order. What I've been using has been fine, and it came on the sale price, so maybe they were thinning out old stock. Speculation !

Bad news anyway.

Jim

 

[Cruiser]

I follow a regime pretty much as Mike has posted.

I use the roller to get the epoxy on, spread it fairly evenly, I find the roller allows me to control the weight of epoxy applied and after going over the area a couple of times, it is a pretty uniform as well. I then drag a brush lightly over the application area to break any air bubbles and the result is usually a pretty smooth finish.



I did this about a week ago, just waiting on the epoxy to be fully cured, so I can sand and move on.


Brian

 

[Jim Dodd]

Glassing Ben's Traveler today, had no problem with the Cigar rollers from RAKA, but I've had them for several years.

We did have some foam brushes swell up though.

Nice glassing Brian ! Bet you hate to sand for varnish !

Jim

 

[Cruiser]

Jim, I am actually a bit impatient to get it sanded, so I can flip and get the inside done. I have the gunnels and the decks ready, so it's just waiting on epoxy cure times.

I just order extra epoxy foam rollers from Noah's, when I order a a batch of epoxy, they haven't let me down yet and they aren't very expensive.


Brian