I'm in the process of finishing some walnut stair railings and posts, using ML
Campbell's UltraStar Clear
I'm spraying with HVLP, (Turbinaire, 1500, 3 stage). 70°F, 30%-40% Humidity.
I started with UltraStar sealer, sanded to 320, I now have 5 coats of USCl
sanding between coats, some at 220 some at 320.
My finish coat still has some blemishes in it, ( some small, very shallow
depressions and some dust pimples).
Through research, the shallow depressions(cratering, fisheye) are possibly due
to contamination or perhaps
drying to fast.
I've added some MLC W-502-4 Water borne flow additive, which helped a little,
but is still unsatisfactory.
If it is contamination causing the cratering, do I sand it smooth, re-seal and
then re-do the final coat(s)?
(I don't know how this happened or what may have caused it.)
Does anyone have experience in rubbing out this particular lacquer finish and
can you explain the steps you
(I've read Jeff Jewitt's site/articles, I'm hoping for some general experience
with UltraStar/Water Bourne
Thanks for reading,
On Apr 10, 5:45 pm, "David" <cosmosatnointerbaunspamdotcom> wrote:>
David - it sounds like your fisheye problem is caused by contaminates
in the finish, in the gun, or on the wood.
Try your finish (from the same can and mixed the same way you spray)
on a clean piece of wood and see if you get the fisheyes or craters.
If so, you know it is gun or finish.
Try cleaning the gun well, and drying it out completely. Set the gun
back up and test it again to see if it has cured the problem. Also,
check out the filter on the turbine. If the filter is dirty, it can
cause the turbine to really heat up and that will cause unpredictable
results in your application.
If that doesn't clear it up, you know it is the wood. If it is the
wood, try some MLC MagnaClaw after sanding, and that should do it. I
believe, I am not sure, but you should be using Magnaclaw on tinted or
colored MLC finshes anyway.
Once the culprit is found, you need to address the problems on your
project. To make a long story short, yes, you have to sand them out.
And unlike solvent based which I find to be more forgiving, you have
to sand the craters out SMOOTH. Anything you leave behind will simply
reflect itself out into the next coat where you will build it back
with subsequent coats.
So get the gun problem fixed first. Try it out on a piece of plywood
or a good sized board. Put the same amount of coats on your test
piece as you do your finish. (Check into that Magnaclaw, too). Then
once a 100% on sealer and applicator, sand out your work as needed and
then recoat to proper thickness. I am not sure, but I think UltraStar
is 3 mil.
If you are going to sand a great deal to knock down the nibs, craters
and fisheyes, you should plan on a final coat of about 6 mil, sand
down as needed, then top coat that.
The process of "rubbing out" isn't one that is commonly used on
balusters, railings and posts, even on upper end work. You are having
problems with your application, caused by different factors. Trying
to "rub out" the finish on balusters and detailed stairway parts would
truly be a nightmare.
I think you should sand off what you have to smooth, then reapply.
Your temps and humidity are just about perfect for spraying, so rule
that out. If this is an unfinished house, (or finished for that
matter), make sure you have about 12 hours for the dust to settle out
of the air. Tape off your work area the day before. Mix your
product, set up your gun, and do all that fiddly crap outside.
Walk in, spray, walk out.
As a sidebar, one thing that helped me was to extend my hose on my
HVLP. I have a four stage, so I put another 6' of whip on the 25'
hose and just that little bit has helped keep me from stirring dust as
I don't have to move hose and machine so much.
For more information that you would think possible on MLC products and
how to use them, go here:
It is not a friendly rodeo atmosphere forum like this one where you
can post your odd questions at will. Every post is completely
monitored, and Bob will throw you off if he thinks you are just some
noob (right or wrong) looking for someone to tell you how to paint a
doghouse. I would strongly suggest you search the archives before
joining and posting.
Jewitt sells Target product, and I don't know if he is selling MLC now
or not. But let me tell you, I would be astonished if you couldn't
find all you need by searching the archives at WoodWeb. That's MLC
country over there.
[ snipped very informative and helpful response].
Indeed. Woodweb is full of good stuff. A genuine resource for pros and
semi-pros alike. It's moderated, so never any trouble with global
warming bushlshit either. (I hear they shoveling some warming stuff in
Thanks for all the great information.
I have re-cleaned my gun, tried some different airflow/product flow combo's but
still had some problems.
I cleaned the turbine filters, but heat build up didn't seem to be a problem, my
spray time is only a couple
I added a little more of the MLC flow additive, that helped a little.
One of the tips I gleaned from the woodweb site was a wipe down with ammonia
After sanding out the problems and a wipe with ammonia, the spray finish was
almost blemish free.
I now am getting a number of tiny bubbles, some of which dissipate with drying.
I'll add a little more of the MLC flow additive on my next test to see if that
It looks like I'm going in the right direction now.
I know you suggested that rubbing out the finish was going to be a nightmare, I
don't disagree, but,
if I can't get the 'off the gun' finish blemish free, what options are there?
The desired finish/sheen is satin or a little less.
On Thu, 12 Apr 2007 19:58:29 -0600, "David"
My newsreader missed the original message.
I spray lots of ML Campbell waterborne lacquers with great success. I
normally spray them directly from the can, via a Fuji 4-stage HVLP
gun. With a suction feed cup or pressure pot, I use a #3 setup, with
a gravity feed, I go up to a #4. I add nothing, no flow additive,
As for the bubbles, you're not shaking the finish can, are you? Don't
shake the can.
For what most folks consider a "satin" sheen, you probably want the
dull product, not the satin. Satin Ultrastar is noticeably more
glossy than most folks think of satin.
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