Help with polyurethane application....

[RaptrFlite]

Haven't posted for a while cause I've had my hands full with the 2.5 year old, so 'hi' to everyone again! I trust everyone is still loving their 3100 as much as I am....

I have no choice but to admit... I can NOT seem to apply the poly correctly.
I stain, then when I apply the poly, I get bubbles and bumps no matter what I do. I then try to lightly sand with 220 grit, before I am about to apply coat number two and end up with a piece that looks distressed and antique (pretty cool actually, I'll probably use that in the future) . Anyone help out a finishing newbie?

btw: It's a kiddie dress/hat rack made of poplar....

All always, thanx!
Mike

[windmill]

How are you applying the poly? Brush? Roller? It is possible to get a smooth, even coat of polyurethane, but it's not easy.

- Ensure the room is free of dust. Every speck will show
- Use a high quality brush. The cheaper the brush, the more skill you need
- Rollers leave bubbles. On large surfaces, consider rolling it with a brush, then going over it with a brush. That gives a reasonable result
- Make sure the ambient temperature is ~70 degrees. Make sure the poly and work piece are ~70 degrees
- Try thinning the poly. If it's oil-based, use mineral spirits. If it's water based...never done that. I guess you could thin it with water, but that's speculation.

You may want to consider buying wipe-on poly. You can get that at your local home improvement store. You need about 2 coats of wipe-on to get the same protection as one coat of regular poly, but it's pretty much foolproof.

Bas.

[cabinetman]

You didn't say what method you were using to apply the poly. Try wiping it on. Make sure that the stain is completely dry. Use a "T" shirt type rag and fold to a square of about 3". Dilute the first coat or two of oil base poly with 50% mineral spirits. Wipe in the direction of the grain, but don't keep going over the same area. Just apply a thin smooth coat. The next coat dilute less like 25%, and maybe put down 2 coats. Some applications you might go to full strength some not.

Allow each coat to thoroughly dry and see how it looks. Try this first on a sample.

If you are brushing it on, if you can afford it use a badger hair brush and dilute the oil base poly by about 25% for the first coat, and use a feathering motion, so as not to leave brush marks. Make sure there is enough material on the brush so you don't drag a dry brush. When ending a stroke, lighten up and lift toward the end of the stroke. Brushing is a matter of technique. After a few coats use full strength.

[Slik Geek]

Missed in the previous helpful posts were:

Make sure that the surface is absolutely clean prior to application of the polyurethane. (And do that cleaning in a reasonably dust-free area or your cleaning will be in vain - and do it right before you apply the finish, after you have stirred it up). A cloth with minerals spirits works pretty well for this.

How are you mixing the polyurethane? Don't shake it!!!! You'll suspend air bubbles like crazy. Stir it gently, pulling settled solids upward as you stir.

BTW: as you apply the polyurethane, picture yourself gently caressing the wood instead slopping on paint in a speed competition. (Yes, that sounds stupid - but I find that my state of mind greatly affects my application technique). The object is to avoid creating air bubbles all through the process.

[gerti]

How are you mixing the polyurethane? Don't shake it!!!! You'll suspend air bubbles like crazy. Stir it gently, pulling settled solids upward as you stir.

Yep. If you were used to rattle-can spray finish you will be tempted to shake. Don't! Did that once, had to sand it back of. Tiny bubbles everywhere.

Also another vote for wipe-on (or even Rockler's Gel PU). Much easier to use.

And do resist the temptation to try an smooth it out. Apply it, feathering with the previous strokes, then leave it be.

[MBG]

I went to wipe-on ploy a few years ago. I dilute polyurethane with naphtha 50:50. It takes 6-8 coats but they dry very fast and don't allow much dust to stick. I also dampen a lint free cloth with some naphtha and wipe down the surface before every coat. I sand after the third and before the last coat.

I also recently tried poly-gel from Rockler and had good results.

Maybe try you finish on test pieces first until you get the technique down.

Mike

[RaptrFlite]

DOH!!! It was shaken, not stirred.... I was using a relatively inexpensive brush and following the wood grain. I'll try the wipe-on and put the 'Fool-proof" lable to the test . thanx to all who answered, I think you hit the mark.

Any thoughts on why my between-coat sandings just look scratchy and weathered? 200-grit too rough? operator-error?

mike

[cabinetman]

When dry and then sanded, the oil base poly gets a bit scratchy and hazy looking. Sand only with the grain between coats and you could use 220x, but 320x will leave a smoother surface to topcoat. Make sure you get the surface dust free and it would help to blow off the surface as the white sanding dust may get into cracks, crevices and holes from the sanding,
.