Craters in My Water Based Poly !!!
#7
  
Would appreciate any helpful comments:

Spraying General Finishes High Performance Water Based Polyurethane, gloss, on the sides of some oak drawers.  I have used this product before and never had any issues until now.

When I spray on the product, initially it appears even distributed with a mirror like contour when viewed from a low angle.  However, as it dries, it assumes an irregular contour, resembling perhaps small craters with surrounding ridges.  Please refer to the photos attached.

In response, I have tried sanding down the irregularities, then cleaning with naphtha,  and then spraying the finish again.  I even tried without using any extender (a retardant the GF sells).  Same phenomenon occurs, perhaps not as bad.

If anyone could:

1) Tell my why this is happening
2) How to prevent it
3) And the existing messed up finish shown in the pictures.  What do I do with that?  Sand it down and start again?

Thanks in advance.


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#8
  Re: Craters in My Water Based Poly !!! by Steve Soldo (Would appreciate any...)
Have you got too much material coming out of the gun? Looks like the surface is flooded and pools.
Also wonder if the water and solvents are seperating. Does the finish in the can mix ok?
Steve





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#9
  Re: RE: Craters in My Water Based Poly !!! by Stwood_ (Have you got too muc...)
(02-09-2019, 02:46 AM)Stwood_ Wrote: Have you got too much material coming out of the gun? Looks like the surface is flooded and pools.
Also wonder if the water and solvents are seperating. Does the finish in the can mix ok?

You are correct, that there appears to be too much material so I lessened the output.  This helped some.  Yes the finish does mix well, there is no separation in the can.
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#10
  Re: Craters in My Water Based Poly !!! by Steve Soldo (Would appreciate any...)
Is this a refinishing effort, or are these new drawers?
I started with absolutely nothing. Now, thanks to years of hard work, careful planning, and perseverance, I find I still have most of it left.
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#11
  Re: RE: Craters in My Water Based Poly !!! by fredhargis (Is this a refinishin...)
(02-09-2019, 07:36 AM)fredhargis Wrote: Is this a refinishing effort, or are these new drawers?

Same question, because it looks like some sort of contamination to me, either silicone or wax on the wood or oil in your air assuming you are using a compressor driven gun.  The film also looks way too heavy to me.  If it's turning blue when you spray it on it's too heavy.  

You can overcome silicone contamination by wiping several times with a clean paper towel with Naptha or mineral spirits.  Oil in your air you have to solve upstream, and also put in a mini filter right before your gun.  

I would strip off what you now have with a chemical stripper and start anew, first with a coat of Sealcoat shellac which will seal in any residual silicone or wax.  

John
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#12
  Re: RE: Craters in My Water Based Poly !!! by jteneyck ([quote='fredhargis' ...)
Looks like too much product was applied but I would place some naphtha on a glass surface and let dry to see if there is any residue.  Some naphtha's can leave a little oily residue.  Roly
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