Poly question

[Los_Lobos]

Hello all, making a few outdoor board games for the show next month. These are 3'X2' framed and 3/4 ply attached to the top. Two coats of primer, two coats of paint and then five coats of poly, all water based for easy cleanup. Had three coats on a set of green nascar boards, lightly sanded them with 320 and put down the fourth coat, went out this morning and this set of boards was all streaky and milky looking where the streaks were. Never had this happen before. Any ideas on what happened? Coated three sets yesterday but this set was the only to do this.

Thanks Les

[TDHofstetter]

I'm at a loss... I've never used water-based poly before. They didn't freeze before they cured, did they?

[Los_Lobos]

Tim, I keep the shop at about 57 thru the winter. This was the last set I did yesterday, could the poly have settled in the can to make this happen? It was about twenty minutes without stiring the container.

Les

[sawduster]

You might check the can for the working temperatures recommended. You might have dodged a bullet on the others that dried clear. Could also be that the little extra thickness of the "streaks" allowed the finish to film over leaving some uncured finish underneath. They might clear up with time.

[jb34]

Was it satin poly? I have had that happen with satin poly. I thought it was because I didn't mix the poly well enough.

[Los_Lobos]

See the streak in lower right corner, I am now thinking it was to cold, air temp may have been 57 but surface may have been colder. Will this still clear up? If not how do I fix this?

Thanks, Les

[TDHofstetter]

I think the only way to know for sure would be to heat it up, get it good & warm. If anything'll do it, that'll be it. You might try a blowdryer on it, even, to get it just a little beyond your comfort range.

If that DOESN'T do it... then you're down to sanding that spot out & reapplying the poly there.

This is sprayed? Is there any chance you had moisture in the air line? Got a water/oil separator out near the gun?

[cabinetman]

Working temps for WB polyurethane is 65 degrees and higher, which also goes for the subject material. You didn't state if it was sprayed, brushed, rolled, or wiped.

Contents in the can should be stirred not shaken, and filtered each time it's used. It works best when sprayed, but in any case thin applications. It dries to the touch usually in 20-30 minutes, but it could take much longer, even days for a complete cure. In heavy applications or puddling in areas, streaking and/or cloudiness can occur.

You might wait it out to see if it clears, or sand, or strip. Lacquer thinner will remove dried material.

[Los_Lobos]

Sorry for not letting you know the application I used, it was a brushed on finish.

Tim, I will try the hairdryer trick and see if that will clear it up.

Cabinetman, yes it was applied in to cold an environment, if Tims idea does not work I guess I have to try and sand it down again.

Thanks, Les