Thread: Bote Cote.

Yes give it a scrub with a scotch brite and detergent or cloudy ammonia first before you start sanding to remove any wax.

220's pretty coarse. Use that to quickly knock off any high spots and then go as fine as you like prior to varnishing - the finer you go the better the finish and don't forget to wipe down with thick rag damped with thinners or acetone to remove any dust.

As an aside, with table tops and the like it's a neat trick to lay a thick acetate (or similar hard plastic) over the wet goo and squeegy any air bubbles out. Peel the acetate off once the goo has set (acetate will not stick to epoxy) and you end up with a super glassy finish. If it's for interior use I wouldn't even bother varnishing.

I generally agree, but I do dislike Scotch Brite pads, as they leave lots of tiny green (okay color depends on the grit) things everywhere. Sure you can clean them up, but they get everywhere and are easily stured up when moving about.

220 is fairly coarse paper, unless you are planning to paint, in which case it's just fine, if not overkill for most paints. For bright finishes (varnish, polyurethane, etc.) I wouldn't go over 380 grit, as you might not have enough "tooth" for the clear finish to grip. I rarely go over 320 as these sanding scratches, if with the grain can't be seen.

Also when you use a palm sander or DA, it will leave swirl marks in the epoxy. Of course you will not notice these until you go out in the sun and see your bright, new, clear finish and all the tiny little sanding marks. Trust me, you'll want to kill yourself.

Always do your finial clear coat sanding with the grain and by hand. This is the only way to avoid swirl marks.

I would go over it with 600 and only by hand.
This assumes your surface ends up pretty good.
Leave the electric sanders alone if you want a really good finish.
It is no slower to sand by hand, as long as you keep your paper renewed.
Ofcourse constant wiping off as has been said, is very important.

Paul.

600 grit is not sanding it's polishing, which doesn't offer enough tooth for the clear coatings to grip.

Hi PAR,
I always finish with 600, before final coat.
Never had a problem ever.
I wish 600 would polish a surface, what a time saver.

Paul.

You will not find a single coating formulator or manufacture that recommends that fine a grit, before another coat. I'm glad you've had good luck.

Must be just good luck.
But I will stick with my tried and true method, which works for me.
I have been using pretty much the same methods since about 1970.
No probs yet.
But you have me worried now.
I shall have to do some reading on the matter.
Thanks.
Paul.

Originally Posted by HOOKED.UP

I have been using pretty much the same methods since about 1970. ...
I shall have to do some reading on the matter.

He's been doing it for 40 years and NOW he decides to read the instructions

Obviously he's a Paul, not a Paula

Richard

actually, they're both 'Paul's

INSTRUCTIONS. ? ?

Daddles, between you and PAR, I am now really worried.

I always though the paper wrapping around those containers, was for product advertising.

I started using the full range of EPICRAFT products in the late 60s. I never remember any instructions which said not to get the best possible finish on any product, before apply your finish coats.
Hence my ignorant use of fine wet and dry.
When I was taught to spray paint, it was by an automotive finisher.
He regarded 600 as a course paper.
I run about the 2000 mark between finish coats.

Just me. Still happy.

Paul.

Paints and coatings have changed dramatically in the last 30 years, hugely in the last 20 years and substantially in the last 10 years. If you want to apply paint like they did when most of its volume would flash or bounce off the surface 30 years ago, then you're not taking advantage of film properties in modern paints and coatings. Hell, now you can spray over a wire brushed surface and get a pretty good finish without buffing, rubbing, color matching, compounding or any of the other things that use to be required for a nice paint job.

You do what you think you need to, but I'm getting mirror finishes with a lot less work then I used to have. The surface prep is still the same. It has to be fair and smooth, but I'm not grinding down through half of the paint film thickness that I just applied, to get it to smooth out any more. I'm using Sterling top coats with a true epoxy primer. I've used AwlGrip, other LPU's and WR-LPU's too, I'm just getting a real good price on Sterling. If I have some stipple or other imperfection, I can buff it out, no need for more coats, once the base film thickness is reached.

The best thing to do is perform a peel strength test on a well prepared bit of scrap. Treat it just like any other paint job. A very simple cross hatch with a razor and some duck tape should give you an idea how well your paint is sticking.

I happened to be on the phone with my goo guy (I buy direct) he's one of the chemists for the company and I asked him about sanding modern LPU's. He said primers were much more sensitive to this and never should a primer be over 400 grit, which he felt was also too much. His recommendation on primer was 380 maximum or it doesn't have enough tooth for a good mechanical bond. The top coats can tolerate more (higher grits), mostly because they go down much thinner, but there's no advantage to finer grits, unless you can justify less work in smoothing or polishing. He was also animate about the differences in marine/aircraft paints and automotive paints. He spouted off several numbers about film thickness comparisons, but it was metric and I couldn't relate quick enough, but to say the film thicknesses were about twice as thick for marine/aircraft then automotive. He also said there's a big difference in automotive stuff now, compared to the latest in the marine industry. This includes the prep. His top coat recommendation is again no more then necessary (400) to remove minor surface blemishes.

Typically you'd shoot for a 200 to 250 micron wet film thickness, which when sanded will work out at half this. This generally requires three coats. For those of you that don't want to apply this much paint, remember you're sanding half of it away, so it's actually only 1.5 coats when you're done sanding, polishing and buffing. I usually apply more paint then is necessary for this reason, which leaves me room for repairs, blending and maybe the need to knock down some over spray or some thing.

yep guys often amuse me with their sanding finer and finer . not needed and a waste of time and energy.
when i was sanding and polishing floors ( timber , parquetry , and cork ) for a living we would fine sand to 100 grit for the first coat then cut back between coats with 100 grit "screen backs" which look some thing like mozzie screen material but are abrasive .
2 or 3 coats and i could achieve an absolute glass like finish using one pak or 2 pak finishes , and never used anything finer than 100 grit . my brother and my brother inlaw are still in the industry and i think they now use 120 grit .

All this discussion about grit is all very well, but I'm curious about the mixing ratio.
The little bit of Bote-Cote I've used has been 2:1 resin to hardener.
What's this 1:1 stuff of which you speak Texmex?
cheers
AJ