Is sanding absolutely required
#1
06-19-15, 08:55 AM
Is sanding absolutely required
Replacing some flat bifold luan closet doors (60" 4 panel) and the related trim around the opening. Staining everything is done finally (very hot here so I basically have only been working 6-8AM and 9-12 PM) and now it's topcoat time.
I had a can of semi-gloss Minwax polyacrylic and I just put the first coat on the trim after it had dried for 24+hrs. I don't know why I had this can or what I used it on before. When we first moved in I know I used varnish on the baseboard I replaced, so this must have been something else. It was open but almost full.
So, to the meat of the question, is it really imperative that I sand before the next (and probably final) coat? The first one soaked in nice and even it seems to me. No glossy or thick spots that I can tell. It's not that big a deal on the trim, but sanding the doors between coats will be kind of a pain.
It doesn't have to look great (we're trying to sell and just match what is in the other rooms) but I don't want it to look crappy.
We would have gone with mirror bifolds, but those things have really gotten expensive I guess.
Thanks
I had a can of semi-gloss Minwax polyacrylic and I just put the first coat on the trim after it had dried for 24+hrs. I don't know why I had this can or what I used it on before. When we first moved in I know I used varnish on the baseboard I replaced, so this must have been something else. It was open but almost full.
So, to the meat of the question, is it really imperative that I sand before the next (and probably final) coat? The first one soaked in nice and even it seems to me. No glossy or thick spots that I can tell. It's not that big a deal on the trim, but sanding the doors between coats will be kind of a pain.
It doesn't have to look great (we're trying to sell and just match what is in the other rooms) but I don't want it to look crappy.
We would have gone with mirror bifolds, but those things have really gotten expensive I guess.
Thanks
#2
06-19-15, 09:01 AM
Sanding will insure that the next coat adheres to the previous. If you don't sand it might be ok .... or it might peel some later on.You don't need to do a heavy duty sanding, just enough to scuff it up. Don't forget to wipe off any sanding dust.
#3
06-19-15, 09:10 AM
Group Moderator
Besides adhesion....
If you run a cloth or paper towel over it (picture the day you go to dust or clean the woodwork) the cloth will probably snag on all the little bits of dust or wood particles that could be in the finish. Sanding will remove those imperfections so that your next coat will be smooth. A very light once over with 220 grit or a 3M fine sanding sponge is about all you need to do. If you sand too hard, you will sand through the finish and into the stain which is bad.
Is it imperative? Not necessarily, but the instructions on the can surely recommend it. Would I skip it? No.
If you run a cloth or paper towel over it (picture the day you go to dust or clean the woodwork) the cloth will probably snag on all the little bits of dust or wood particles that could be in the finish. Sanding will remove those imperfections so that your next coat will be smooth. A very light once over with 220 grit or a 3M fine sanding sponge is about all you need to do. If you sand too hard, you will sand through the finish and into the stain which is bad.
Is it imperative? Not necessarily, but the instructions on the can surely recommend it. Would I skip it? No.
#4
06-19-15, 09:43 AM
Ok, I get it. Light sanding it is. It was actually removing the dust that concerned me most. I figured, hey, if I don't sand, there won't be any dust boogers. I'll dig out/make a tack rag. I think I still have one somewhere.
#5
06-19-15, 10:39 AM
Group Moderator
Vic - the idea is that poly cures rather than dries so in order to get good adhesion between the coats you create nooks and crannies with a light scuff sand so the new poly can flow into them and create a mechanical bond between the coats. Lacquer, on the other hand, dries so the next coat slightly dissolves the previous coat and bonds them together so scuff sanding between coats of lacquer is only needed if you find some reason that you need to smooth the finish.
#7
06-19-15, 08:43 PM
Well, this has been a royal PITA. The trim not so much, but JHC the doors are taking forever. I should have just volunteered to pay 1/2 the cost of mirrored doors.
Every little scuff or scratch stands out like crazy, Guess that's why they are basically considered paint grade.
Only about half done, and I'm thinking the backsides of the doors will maybe get one coat...max.
The 95 degree heat doesn't help...it dries so fast I can barely keep a wet edge.
Every little scuff or scratch stands out like crazy, Guess that's why they are basically considered paint grade.
Only about half done, and I'm thinking the backsides of the doors will maybe get one coat...max.
The 95 degree heat doesn't help...it dries so fast I can barely keep a wet edge.
#8
06-20-15, 03:16 AM
Sometimes it's beneficial to thin the coating a little when you have to apply it in hot/dry conditions.
While I didn't agree with it, I used to work for an outfit that never finished the backside of closet doors. The painted ones just got primed and the others just got stain or nothing
While I didn't agree with it, I used to work for an outfit that never finished the backside of closet doors. The painted ones just got primed and the others just got stain or nothing
#9
06-20-15, 06:29 AM
Well, the doors are completely stained already, I think one coat of clear on the back will be enough to seal it. No reason for more if it will never be seen once installed. Bifolds after all.
