thanks in advance for some input on the following problem. I just spent a long time building a mantle with lots of curves. tricky and labor intensive. even though it was probably fine this morning and ready to install, i just had to go ahead and add another coat.
well, two problems. my spray gun began to malfunction and as a result I laid it on a little heavy in spots and now I have a sag or two. suggestions?
part two : the pilasters finished semi-gloss as they were supposed to, but the crown trim is as shiny as bright work. same can of varnish, same spray gun, same prep. whats wrong?
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this larger picture might be better -- but it'll be a slow load
I can't help you with the gloss vs matt problem, other than to rub it all down with something appropriate (steelwool, scotchbrite, you pick your poison).
As for runs (which I didn't see in the photo), some folks ( ;-) ) have been known to use a scraper to remove them.
hows this sound -- what if I took 0000 steel wool and rubbed in some wax on the flatter areas of the finish, at least that might shine them up enough to match the rest more closely. would the wax last ok?
The wax isn't going to give you the same sheen as the rest.
In regard to your spraygun problem. If more finish was applied in some areas than others, it will appear to have a brighter shine. What kind of gun are you using? That could be one of your problems. Sometimes, the quality of the finish isn't always the person standing behind the gun.
I noticed you had a burn mark on the flute from the router bit. I get them all the time when I do stop flutes. If you have a local refinishing company, you might want to ask them if they can "Base it out" Basically, they take pigment and blockout the burn mark and then blend the rest of the piece together. I have some friends who own a refinishing company and they do it for me all the time. It's a pain in the butt to sand out the peskey burn marks.
I would take some 220 sand paper, rough up the finish all over and re spray it. Becareful not to put too much finish on or you could end up with the finish peeling.
thanks for the pointers -- I see that you're right about the amount of varnish -- the devilbiss gun was a good one in it's day, and even though I broke it down and cleaned it pretty well, it began to spray less volume as I went along. felt like a feed issue rather than supply. almost dusting some areas rather than liquifying. the brand is minwax 'helmsman' spar urethane. (I'm not blaming the varnish) no catalyst, and I didn't thin it. In many years of spraying, I've never had such a messed up finish.
yeah, there were a lot of burn marks and I managed to mitigate most of them -- but you're right it needs a little more attention.
so 220 paper isn't too coarse?
I am usually more comfortable with 320 between coats, for less chance of cutting through, though another varnish coat will likely cover 220 grit without any sanding marks showing through. 320 is plenty for good adhesion.
I agree with the suggestion to flatten sags with a scraper--light touch needed. The scraper lets you attack the sag without removing surrounding finish.
I would also check to see if adding a bit of thinner to your varnish wouldn't help it spray more easily. Many varnishes have been reformulated in the last few years to reduce VOCs and consequently now need thinning, even for brushing. (Labels may say not to thin, but that is to satisfy regulators, not to make the product work better.) One point on satin finishes, which you probably know, is to be sure to keep them stirred up since the flatting agent can settle out, making one batch from the can different from another.
You may want to try the steel wool rub out first, it would tend to leave everything with a satin finish. Spar varnish isn't the easiest to rub out to a sheen however.
I tried the scraper, and it seems the varnish was just too soft, even after 30 + hours. I put some heat to it overnight and it hardened up enough to give it a light buff with 220, so I brushed on another coat this morning. it is also drying more flat than the trim, so, I guess I didn't stir it up enough or keep all the particles suspended. anyway, looks like I'll go get another can and brush on yet another coat -- it says recoat in 4 hours, I shouldn't need to sand first should I?
How did you get the sags out before recoating?
If you could recoat right at the 4 hour window sanding wouldn't be too important--better but not absolutely necessary I don't think. However, you already have a drying problem if you couldn't use the scraper after 30 hours, probably because of too thick application. So don't add another coat until everything is really dry. While you may end up having to do more drastic things, I would give this some extra time. And keep the heat up--70° F. at least--for a week or more, and then see if you can rub this out to a more even sheen. Satin can be rubbed out to a bit higher gloss with fine abrasive, but you need to get the sags out first. Ideally, you would wait a month before rubbing out.
In the last couple of years I haven't seen any oil based varnish that didn't need thinning so that may be part of the problem. Unlike conversion varnish, spar varnish should tolerate a fairly thick total film build, but it is best applied in a larger number of thin coats.
It appeared to me as though he was putting on too much finish and that's why I suggested using 220.
Now, after reading another post from the member on how after 30+ hours, I'm confident that is what he did.
I hate to tell ya this, but you're going to need to strip the piece or sand it all out with a power sander.
I don't know if you've used that finish before, but from what I remember, it's very thick.
You need to have it in a consistancy of a thick milk. Still watery, but has some solid too it. More light coats are better than a few heavy.
If you're a professional cabinet shop, you can order the real conversion varnish.
If some is very shiny and other places matte, the flatting agents probably had settled out.Gretchen
thanks everybody -- well, with a bit of doing I've managed to get it up to speed.
I ended up sanding it down very carefully and thoroughly and re applying a 'well mixed' batch of the same varnish, and it's come out ok. not unbelievable, but pretty good.
this time I didn't spray it -- I brushed it.
Something else just popped in my head. Who's finish are you using and do you have to add catalyst before you shoot it?
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