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blueman blueman is offline
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Default Sanding/buffing/polishing epoxy clear coat top

"Mike Marlow" writes:

blueman wrote:


I ended up doing the following:

1. Applied about 6 coats of West System 105 Resin with 207 Clear coat
hardener using a dense foam roller. However as mentioned above, the
roller itself seems to have deposited random fine nibs. I estimate
that the total final thickness was about 30-40 mils. Finish was
applied to all sides including the top, bottom, and sink cutout
area.


You'll soon want to get past that damned roller. Stick around long enough
and we'll have a spray gun in your hand.


I recently picked up the "high quality/high price" HVLP gun at HF which
had decent reviews and I assume corresponds to a low end hopefully
acceptable non-HF brand

However, I haven't had the time/guts to try it yet. And I assumed that
spraying epoxy is not the right place to start for beginners. I am right
in assuming lacquer might be a good first start?



2. Started sanding at 220 which was enough to knock down the specks
and smooth out imperfections


I see you are a glutton for punishiment...

Yeah - I put so much time into it that I wanted to get it "right" even
if it took longer.


3. Wet sanded up to 3000 in increments as follows:
220-320-400-600-800-1200-1500-2000-2500-3000
Probably way overkill but I had the sandpaper from my "Scary Sharp"
method of sharpening steel


Oh stop - you just wanted to do all those steps. Woodworkers can be that
way. Can't tell them a damned thing...

LOL - I was being belt-and-suspenders having invested so much already...



4. Switched to a power buffer with a wool bonnet (bought for about $25
at Harbor Freight)
At first I tried various colored buffing compound sticks but they
did absolutely nothing (probably because very little compound
seemed to transfer to the bonnet from these hard sticks -- perhaps
I was doing something wrong...)


See - ya wouldn't just listen to me, would ya?

Mea Culpa - and I will know next time to listen to you over other
opinions...
In fact, I got a mix of opinions from various people so I tried the
sticks first since they had them available right next to the
buffers. When that didn't work, I made another trip to the auto supply
store...

By the way, what if anything are those sticks useful for? It doesn't
seem like they "charge" the bonnett with much if any compound so I
wonder how it ever does anything unless I am using it wrong...


So I switched to Automotive rubbing & polishing compound (given that
I had already sanded up to 3000 grit, I found that I could start
with the polishing compound and skip the rubbing compound). The
compounds come as loose pastes that I applied quite liberally to the
vanity surface before buffing.


Yeah - but it takes more work. I'd have hit it with a medium to fine
rubbing compound and then just cleaned it up (if even necessary) with a
swirl mark remover.


You're probably right but my thinking is that having gone already to 3000
on the wet-dry sandpaper that maybe I was "beyond" the rubbing
compound. Didn't take much work with the polishing compound to make it
work though...

For the future, if I go with the rubbing compound, what grit (if any) do
I need to hit it with first with sandpaper -- i.e., do I still need to
sand up to grit XXX before starting to buff with rubbing compound?

Also, is swirl mark remover different from polishing compound?

Finally, how do I get a handle on the different grits and types of
rubbing vs. polishing compound. It wasn't clear from the labeling on
the various tubes and tins at the auto supply store what the differences
are?



I ended up buffing at the highest speed (~3000 rpm) after gradually
ramping up and testing for damage. Note that the buffer never seemed
to damage or dig into the coating too much even with some pressure
and even with extensive buffing - probably due to the hardness of
the epoxy. So, while I was careful, the epoxy coating seemed to be
pretty power buffer friendly. Of course, I kept the buffer moving
to avoid swirl marks.


On flats that's ok. Just be carefule around edges. Even that epoxy finish
will succomb to a buffer around edges. The worst thing you can do with a
buffer is to become overconfident. That only happens once... in a while...


I agree - edges are always dangerous...



After this the top was BEAUTIFUL and clear like glass -- in fact, if
anything the biggest compliment (and maybe criticism) is that it looks
like glass and not like the wood people are used to from projects.


Oh - what the hell do they know?


However, I think it is still less shiny and sparkling than the
absolutely crystal clear reflective finish from the original epoxy
topcoat. But since the entire top has been polished uniformly, one
doesn't notice that. And it probably looks richer to not have a
mirror-like reflecting surface that catches all the glare.


Picky, picky, picky.

Glad to hear it came up nice for you.

Thanks -- after my initial failures with getting a nib-free coat and
with ordinary sandpaper, I was beginning to despair. But in the end, it
came out more beautiful than I could have imagined -- I am embarrassed
to admit how many times during the first few days I sneaked a peak and
"copped" a feel of the surface to "admire" my handiwork.

Thank a million again for all your help and the input of others!!!