Polyurethane Not Drying?

**TheEmptyCell** · #1 10-18-2007, 04:55 PM

I've been working on my SR506, and got to the point 4 days ago where there was 3 coats of poly on the board, but then found there were certain spots where the poly was very tacky, even after long drying times. I removed it all and started again, but after 1 coat and a good 12 hours, the exact same spots are tacky.

There was nothing on the fretboard when I sanded it down to 1000 grit paper. It was baby-butt smooth. I'm using Minwax oil-based polyurethane. I'm not comfortable working ith any sort of epoxy, so should I try something different? Tung-oil? Water-based poly?

I used a Minwax water-based poly on an old defret, and it didn't do this. Any other suggestions or ideas? I'm desperate before I just decide to leave the board uncoated.

Lonnybass · #2 10-18-2007, 05:11 PM

Have you tried a little wetsanding with mineral spirits? Could be that the poly went on a little heavier in those areas and is taking longer to dry and even out.

Lonnybass

**TheEmptyCell** · #3 10-18-2007, 05:35 PM

What exactly will that achieve? I know the poly says to sand with 220 after each coat, but even when I sanded the first time, it came back with the stickyness.

And it's sticky this time, after 1 coat of poly, in the exact same places. Will the mineral oil clean whatever is there off or something? I'm no woodworker, I'm just doing this so I have a fretless and actually use the 6 string.

Now, if I do wetsand, should I use the 1000 grit paper? How should I wet the paper? Sorry for the n00bish questions, and thanks a ton!!!

Lonnybass · #4 10-18-2007, 05:46 PM

Wetsanding will act like a polish and could smooth out the feel of those tacky spots. Try pouring a bit of mineral spirits straight from the can onto your sandpaper surface and then with a light pressure start to sand.

Another suggestion would be to hit the coat of poly with a light once-over of 0000 steel wool.

In my experience, the 220 that Minwax recommends is still WAY too coarse for a good smooth coat - you should go up to 1500 if you really want it to look good and without scratch/sanding lines.

Also, don't forget that you may want to let it dry a full 24 hours before you do anything. The can says 2-3 hours but that's in the best conditions, temperature and humidity. Give it some extra time to set up and see what happens.

Lastly, you'll get much better results with multiple THIN coats than trying to put the stuff on heavy.

I just finished a bass using Minwax poly and tracked the whole process with photos. Here's a link to the thread - go through it and there might be some stuff in there that helps you.

Warmoth build starts TODAY

**TheEmptyCell** · #5 10-18-2007, 06:04 PM

Thanks a bunch! The first time, I'm pretty sure I went on heavy, but this time around I made sure to go on light, and even ran another brush over to thin it down more. I'll give it till tomorrow morning and then see how it is. I sanded with 320 between coats last time, but this time I'm going to do it with my 0000 wool.

scottyd · #6 10-18-2007, 06:24 PM

Poly doesn’t like to play well with most rosewood. If its cocobolo it may never dry depending on the oil content in the wood. You need to wipe the board down with acetone very well before you start to coat it. A little trick I found is to use a satin poly for the first few coats. The satin dries faster and seems to dry better with the oilier woods, it also seals it. Scuff that with some 400 grit then finish coat with the gloss poly. I agree that 220 is too rough a grit to go between coats I would use at least 600 wet and preferably 800 wet when you get in the final stages of finish. GOOD LUCK!