Help with Wipe-On Poly over Paint

I have never put poly over paint but had a similar problem with wipe on poly. I came to the conclusion that summer heat & humidity had caused the streaky finish.

Adam

Let me guess is it water base poly?

-- shdesign3.com

hey Steve. Not sure. Its all from a big box store. Regular flat spray paint, and wipe on poly from Lowes. Spray paint isn’t oil based is it? so if it is a water based poly, that shouldnt matter? I will check tomorrow to see which products I used…maybe I’ll post some pictures of them

-- Hey you dang woodchucks, quit chucking my wood!!!!

I would think that krylon and minwax would work well together. That what you used?

-- LAS, http://www.abettersign.com

THe spray paint is likely oil based – so long as it was dry the poly shouldn’t matter (water or oil based).
If it was oil over oil – maybe the streaks are that the poly redisolved a bit of the paint.
I think the only was to sort it out will be an additional coat – it will either be OK or still look streaky, and you would need to sand :-(
You might try spray on poly (spray can or gun) – as it won’t “disturb” the layer underneath.

Look forward to what you find out. When we did this in finishing – using Arti Water based dyes to make the wood black – we sealed with a spray coat of shellac – before building a finish.
Using Oak we did:
Dye
Shellac
2 coats spray lacquer
Then we mixed some gel varnish with Mixol colors – and made a colorwash – in Red or Blue which when wiped on just colored the deep grain of the oak
Then sprayed clear lacquer over it. Goal is to be subtle…hard to photograph with the high gloss – but here it is Red – just the black – blue and white

Througout the class the theme seemed to be that Shellac was our best friend.

-- "_If we did all the things we are capable of doing, we would literally astonish ourselves_." Edison

Here’s my 2 cents, almost all spray cans are lacquer based, therefore you have put a lacquer finish on the wood, and a clear lacquer finish should top it. I have however ran into a few water based spray cans but they are usually labeled very clearly water base. If it dryed very fast and smelled harsh it was probably lacquer, poly will not lay over lacquer for very long.

-- Tom D

Ouch, not good!

My guess is that the solvent (mineral spirits) in the poly (which is quite a bit in the wipe-on products) dissolved portions of the spray paint, which also uses mineral spirits as a solvent. The streaks are likely from finger pressure during the wiping…it wouldn’t take much too desolve a thin layer of spray paint.

Anytime you wipe on a product over the top of something else that uses the same solvent, well, time to strip it down and start over. This happens all the time with stains. If you wipe on something with the same solvent, it will pick up the pigments in the stain and move it around. This is why spraying is often better for such things, though you could solve that issue in the first place by using wipe-on products over something that does NOT have that same solvent. For example, you could use something like an ebony dye (mixed with water or alcohol) and THEN your poly. Dye is better anyway since it cannot be dissolved (it already was dissolved in the first place). Or, you could have been safe by using a seal coat of dewaxed shellac between the paint and poly layers. Or, you could have mixed some black dye into your poly and wiped that on.

Poly builds upon existing coats…it doesn’t work like a lacquer whereby coats melt the coats underneath it. So, putting more poly on will likely make things worse. However, the good news is that if you DO mix some black dye into your poly, then you’ll fix your problems. Basically, the tinted poly will cover the streaks underneath. Heck, I’ve mixed Minwax Ebony stain in poly and got exactly the same look you are describing. I normally coat with a plain coat of poly (or two) over the top.

If you wanted to use spray paint, for your application, you should have used a gloss black enamel spray paint. Enamel paints are designed to be very tough and durable on their own…and putting anything over the top of them will, in fact, cloud up the glossy finish. You wouldn’t need the poly.

Hope this helps!

-- jay, www.allaboutastro.com

BTW, you can always see what the solvent is by reading the label. If it says you can clean up your brushes with mineral spirits, then you know what the solvent is, right? Most of your typical spray paint cans clean up with mineral spirits…all the ones in my shop are that way.

-- jay, www.allaboutastro.com

Deft spray gloss lacquer would have been better… and over gloss spray paint (of which I recommend the Rustoleum Universal). That black is so hard and shiny you may even skip the clear gloss over it.

-- If you're going to stir the pot, think BIG spoon or SMALL boat paddle. David Grimes, Georgia

Hi Doug.What you have is typical for the first coat. It will take many coats to “build” the finish- especially if you want that full finish look…. like “Ikea”. I just did two tables that started out with 4 coats of lacquer sprayed on. I did not like the open grain showing so much so I wound up using wipe on poly for the final finish. I also got some streaking using the wipe on poly with a rag, so I reverted to what I learned from a guy a long time ago and I wrote it on my paint cabinet!! Use naphtha in poly!! This it to make it dry faster to reduce dust and to make it level out better. So I put on the last two coats by pouring the poly in a cup, adding about 1/8 naphtha and applying it with a foam brush. I wet sanded with 400 in between all coats. It came out to almost a full filled finish….........Jim

-- Jim Jakosh.....Practical Wood Products...........Learn something new every day!!

I think the problem here is most probably the sand, I might be wrong but from the pictures, it appears to have been over-sanded. I think you should have used something lighter. And my guess now is that you just sand it all over again with something relatively lighter and repaint it all over.

Just adding another coat of poly over it will change anything. Just my 2cents anyways.

-- I need your woodworking ideas and questions on a Woodworking Survey. You can find the survey on my profile page. Earn a reward after filled up.

I only sanded the wood to 220. So that wasn’t too much sanding. I did sand the paint w/ 600 though. Is that where I sanded it too much?? I will post pictures of the two products I used later today! UGH – I hope I dont have to sand this thing down to the wood again! What a pain in the butt!

-- Hey you dang woodchucks, quit chucking my wood!!!!

I say you should ditch the sanding and the poly and just go with spraypaint and spray finishes. The sprays often take more time to build up, but the glossy sheens are far more “glossy” and “plastic” than trying to do a hand finish. And brush finishes leave more streaks than hand rubbed.

I can’t comment on the compatibility of the paint and the poly. But I can DEFINITELY say that a streaky appearance is perfectly normal for the first couple of coats of wipe-on poly. Because the finish is so thin, it takes two or three coats just to get even coverage. The flat black color on the table is probably just making this more noticeable than it would be on unpainted wood.

-- Charlie M. "Woodworking - patience = firewood"

Get a test board. Put some black spray on it. Let it cure. Wipe on a coat of poly like you did on the table…use a white paper towel. Inspect the towel once finished.

That should let you know the origin of the streaking.

I agree that wipe on poly will show some streaking initially, especially over dark colors, but I thought the pictures looked more atypical of that.

-- jay, www.allaboutastro.com