Help before I freak...

[Filmboydoug]

I am doing up some finish samples for a future speaker project. I bought some nice quality poly, and I sprung for a natural fiber brush. I slowly stirred the poly, making sure I did not agitate it, so...

How do I eliminate the #$%*&# bubbles and brush marks?

 

[skippy_ps]

Doug,

A coupe of years ago, I refinished about 20 cabinet doors and the "facing" of the cabinets. Started out with some high quality bristle brushes and had a lot of trouble with bubbles forming as I moved the brush across the door. Switched to foam brushes and had much better luck. Don't get the cheap ones that come in a bag, they disintegrate in thinner. Try to find the better ones at a paint store and just buy several little and medium size ones.

Flood the poly on pretty thick and you'll get a smooth finish. I put enough on so that it would drip off the sides. Clean this up as you go.

I put 3 coats on, sanded in between with 220 and a 5" round Makita hook and loop sander. Use a tack cloth. YMMV

I also used some t shirt material to apply the poly and it comes out really smooth but is more trouble and takes a little while to get the "hang" of it. Put the rag in a zip lock bag between coats.

Sounds like fun.

Murray

 

[skippy_ps]

Pics!

 

[theNoid]

I have used Minwax poly for most of my poly experiences. The last project I used it with was my TB871 project. I was sure to mix it up good, and to be honest with you, I wasn't being to careful to avoid bubbles. I used cheap little foam "brush" applicators from Big Lots and I had no probs at all with bubbles or brush marks. Inbetween coats I simply threw out the applicator and started with a fresh one for each coat. I went with several coats, and kept them pretty thin for that matter. End result...no runs, no drips, no bubbles, no errors. Just my experiences here...

Noidster

 

[absolon]

If you don't mind a little extra work, use poly that is specialy formulated as a wipe-on finish. Coats go on very thin so you need more of them but it ends up looking more like an oil finish than the heavy layer of plastic you get from brush-on poly. If you have to brush, solvent base works better than water base as it can be applied in thinner coats and takes "rubbing out" much better.

 

[reyneman]

Back in an earlier life when I worked with wood...

I found that an airless sprayer applied poly so smoothly that it made most any brushed on finish look dull. It was also quite easy to do for great results.

If you only have one project, perhaps you can borrow an airless. BE SURE TO CLEAN IMMEDIATELY AFTER USE. If not, have spare parts available.

 

[blackwatch26]

I use a nitrile glove and apply Min-Wax wipe on poly with my hand, rubbing it in until a thin even coat is applied. If more than one coat is needed, I either sand lightly with 600 grit or OOO steel wool then clean off all the sanding dust with an old tee shirt dampened with mineral spirits.

I have done Klipschorns, Heresys, subwoofer, and many amp bases and cases with this method with great results.

Rick

 

[lukez95]

you'll get a better result using high gloss finish. It's harder & doesn't have the particles that semi-gloss or flat have. If you don't want a gloss look, use 0000 steel wool after your last coat. I've used this technique several times and get a glass smooth look & feel.

 

[rallycat]

You can also use some paint thinner to thin out the poly so it has more time to smooth out brush lines & let bubbles pop. Use plenty of ventilation. I read that all the manufacturers have less solvent in current mixes to reduce VOC.

Tom

 

[Fisherdude]

You can apply poly finishes, including poly & stain Minwax, by rubbing it on with a cloth. No bubbles, no streaks. Takes a few more coats, but it works very well.

However, if you want a "vintage" finish that looks hand-rubbed and not glossy, I highly, highly recommend WoodSheen by Minwax. It's an oil finish and stain combo. Wipe it on, let it sit for 5 minutes, and buff it off. The more coats the deeper the color. Try a bottle and do a few test spots on a scrap of wood. I think you'll like it.

If you really want a poly finish, and you're using anything other than high gloss, you need to stir it to mix up the fine powder that gives it a satin or semi-gloss finish. Bubbles are a major problem. You need to stir very slowly over several minutes, working the can from the bottom to the top. Any gloss or semi-gloss finish will require work after the final coat has dried. There will always be a few bubbles or a few dust specks that settle on the finish before it dries. Super-fine wet/dry paper and a final workover with a rubbing compound will leave it super smooth.

 

[toxcrusadr]

Ick. Polyurethane.

Us antique radio guys use spray on lacquer. Dries in 20 minutes, no bubbles, brush marks, or dust that settled in the 24 hours poly takes to dry. Strips a lot easier if you screw it up. Toned lacquer spray cans available in just about any color in case your stain wasn't exactly what you wanted.

Mmm, lacquer. :yes:

PS the solvents will give you a much better high, too

 

[soundmotor]

I found that an airless sprayer applied poly so smoothly that it made most any brushed on finish look dull. It was also quite easy to do for great results.

A sprayer definitely makes sense and as close to a dust free environment as possible. The other critical points are temperature & humidity. If you aren't going to use a sprayer, make sure the finish is well within the rated range. Whenever I paint or lacquer something, I leave the cans in the car for a few hours. When it is warm it will both flow & release bubbles more easily. Always do your finishing on a low humidity day as well even if it means waiting, waiting, waiting. You'll get a better finish if you do.

 

[soundmotor]

Toned lacquer spray cans available in just about any color in case your stain wasn't exactly what you wanted.

You know it!

I am on a first name basis with the people at Mohawk!

 

[soundmotor]

Ick. Polyurethane.

Us antique radio guys use spray on lacquer. Dries in 20 minutes, no bubbles, brush marks, or dust that settled in the 24 hours poly takes to dry. Strips a lot easier if you screw it up.

Could not agree more!

Polyurethane is great for a bar top or marine use, a general pain-in-the-ass for anything else. Being made from liquid plastic makes it especially resistant to scraping & sanding. I screw-up often & lacquer seems designed for that fact. I've certainly seen beautiful work using polyurethanes, but I am generally lazy & seek the path of least resistance. Lacquer all the way baby!