How many coats of epoxy?

**PAR** · 18th October 2009, 03:06 PM

Attempting to save rollers is poor economy, the same is true of brushes. Epoxy when properly mixed will cure, regardless of what you do, except if put it in a sub 0 freezer. Acetone, nor any other chemical can't save it, the goo will undergo the chemical reaction regardless. We use the cheapest brushes and low cost foam rollers. I buy them by the case. No kidding, I buy 2" chip brushes 96 at a time and rollers 100 at a time. I do admit to wasting them on occasion, just because I can, but bought in bulk like this I can afford to toss a few in the trash to make life easier.

There are three basic types of roller materials, fuzzy, foam and better foam. Of course there are many sizes available, but for small items I prefer what they call door and trim rollers here in the states. They're about an inch in diameter and maybe 5 inches long. They take a special handle, which doesn't have a cage, just a rod. They fit into the tights places and have a very close knit cellular structure in the foam, so they lay down a finer, smoother coating. In use you roll out an area, spreading goo uniformly, then by holding your finger against the roller to prevent it from spinning, you light drag across the same area to remove bubbles or you can tip off with a brush to do the same.

Richard is correct, you don't notice the tacky previous coating as the new coating of fresh epoxy acts as a great lubricant. When you do your first few wood laminates, you'll discover how effective a lubricant epoxy is.

Epoxy use boils down to preparation and scheduling. Good surface prep and dry runs before the goo hits the fan, saves lots of trouble. Plan common gluing and coating tasks to take advantage of "goo time". Since you have a limited working time with epoxy, good planning will yield less materials use (rollers, brushes, paper towels, gloves, etc.).

**hereselmo1** · 18th October 2009, 04:29 PM

Man I'm knackered.

Got three coats on one side of the frames today. Took all afternoon. Lovely sunny weather to get it done today.

I have a real problem with the bubbling. Had to keep running the platic comb over it to over and over to smooth them out.

What causes the bubbling anyway? And is there a way of minimising it?

**Daddles** · 18th October 2009, 06:09 PM

Were the bubbles in the mix? If you mix it too vigorously you can create bubbles that get transferred to the job. You can probably make a few by applying it too vigorously too. Epoxy is a nice product - it fills gaps (so you don't have to be a master carpenter) and likes to be handled sedately, my type of goop

Richard

**b.o.a.t.** · 18th October 2009, 08:53 PM

Possibly out-gassing ?
IIRC, today got warmer as it got later.
As the wood heats up, the air in it expands & exits via the pores in the wood.
Blowing bubbles in your epoxy on the way out.

Only way to avoid it is apply pox to wood that is of constant or falling temperature.
Either by doing so after the day starts cooling, or by slightly pre-heating your wood,
and applying your pox before the wood cools to ambient.

cheers
AJ

**hereselmo1** · 18th October 2009, 09:14 PM

Originally Posted by b.o.a.t.

Possibly out-gassing ?
IIRC, today got warmer as it got later.
As the wood heats up, the air in it expands & exits via the pores in the wood.
Blowing bubbles in your epoxy on the way out.

Only way to avoid it is apply pox to wood that is of constant or falling temperature.
Either by doing so after the day starts cooling, or by slightly pre-heating your wood,
and applying your pox before the wood cools to ambient.

cheers
AJ

Yeah that is probably it. There were no bubbles when I mixed or applied it but they appeared after. I wiped them away and they kept coming back.

The wood was stored in the cold damp shed and we were applying the epoxy then putting them out in the sun to dry.

I guess next time I might keep them in the sun to start with so there isnt so much gassing. I need to dry them in the sun or I will be there all day.

**b.o.a.t.** · 18th October 2009, 11:52 PM

Got to be bit careful about pre-heating stuff in the sun... cool one side, hot
the other = warping & distortion & all manner of ugliness. Especially if one side
can absorb moisture from whatever it sits on.

Need to keep the item well ventilated both sides & evenly warming. Best to
heat parts by standing them in a warm room - sun-room / roof cavity.

As you may have noticed, your pox flows best when it is a bit warm - the
difference between runny enamel & thickened acrylic paint.

Also your wood needs to be warm if you want it to go off quicker. My
observation of BoteCote is that cure is more temperature dependant than
sunlight dependant, except to the extent that the sunlight is strong enough
to heat the wood. In winter, sunlight makes sod-all difference compared
with a shed heater switched on well before attempting epoxying.

cheers
AJ

**hereselmo1** · 19th October 2009, 07:06 PM

Thanks again guys you have been a big help. Annoying thing is that I now need to wait a fortnight til I get another day off to do the other side.

I just want to stand the bloody ribs up so that it looks like I have done something

.

P.s. My camera is missing a battery atm. Will post more pics soon.

**PAR** · 20th October 2009, 10:45 AM

If you're getting a bunch of bubbles and wish to get rid of them, use a torch. Yep, a big old propane or MAPP gas torch, like the kind used to sweat joints on copper water pipes. Wave it over the surface, though don't touch it and keep it moving. The air inside the bubble will heat up quickly, which pops the bubble. If you let the flame hit the surface it will heat the epoxy, so you'll just be making more bubbles, but if you wave it just above the surface it works real good.

Out gassing only happens on raw wood or wood that isn't well sealed. On previously coated surfaces, out gassing isn't an issue.

Most bubbles are caused by applying the goo too quickly. People roll the crap out of a surface at 50 MPH with the roller handle and this puts lots of bubbles in the goo. Fast brushing can also do this, but not nearly as well as a roller. Slow, deliberate strokes, you're making love, not trying to screw it up. Strokes should be applied at the same rate each time to control how much goo you lay down. For that matter, put down the brush, it wastes resin and use a squeegee or plastic applicator. Both of these will apply an even, easily controled coating, which is the whole idea.

**jmk89** · 20th October 2009, 02:43 PM

Originally Posted by PAR

... Slow, deliberate strokes, you're making love, not trying to screw it up. ...

A very apt and descriptive distinction, which I shall remember

**VicPete** · 22nd October 2009, 03:37 PM

I have successfully saved on the the number of rollers I go through by putting them in a plastic bag and putting them in the freezer. The next time I use it, I take it out of the freezer prior to mixing the epoxy. About ten minutes after taking it out of the freezer, it's ready to use (depending on how warm the day is).
It seems to work fine if the roller is used within a day or two. Any more and it's no good. The lower temperature slows, but doesn't stop, the curing process.
You can only do it once too. Second time it comes out too stiff.

I have done this successfully to brushes too.
The rollers and brushes come out of the freezer rock hard of course, but they soften up after a little while.

Cheers, Pete

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