Waterborne Finish


From original questioner:

Need help. Does all waterborne clear bubble up on mdf core oak plywood? I am using a orbital sander with 220 blowing it off with air then spraying it with clear. I give it a couple tack coats and when it dries some have air pockets If i do a heavy coat there are big pockets all over. Is that the nature of the waterborn? Is there any waterborne clear that doesnt do that. I use a paint booth and hvlp gun with 26 psi.

From contributor Ji

I always have the best results with thinn coats when useing waterbase.

From contributor Ro

Are there any good waterborne clears that have less bubbles and air pockets?

From contributor De

You are probably applying it too thick. Spray a lighter coat as a sealer, sand and then spray 2-3 more coats. After it is sealed you should't get bubbles no matter how thick it is.

Another thing to watch is how far the gun is from the surface. If you are spraying at 6-8 inches from the surface, back off to 10-12 inches and see if that helps, which it usually does.

As far as products, I have used a myriad of different WB finishes over the past 18 years and currently there are many that are excellent.

2 that are widely available are MLCampbell Aqualente and General Finishes Poly. I would personally give the GF the nod between the two. There are also other fantastic products from ICA and other European companies.

From contributor Ro

i try to put a light coat on then wait about 15 min then spray another light coat then let dry let set for 1hour then sand with 220 ros lighty blow off with air put in paint booth apply couple light coats let set for 15ish min then thats when i put 3 mil coat and then bubbles come out

From contributor De

It is possible that 15 minutes is not enough and the solvent is not finished flashing off when you spray the second coat 15 min later.

It may take some experimenting depending on temp and humidity but maybe 30-60 minutes would give better results.

One other thing I would like to mention is that all of the major companies have a sanding sealer that works with their clear coat and you may want to give them a shot.

One other thing, Oak and open pore woods will always have more grain raise and rough textures with WB on the initial coats. Over the years I have learned that for us the best finish comes when we spray 2 light seal coats and then let them dry overnight. Then sand with sanding sponges, clean and shoot one or 2 more coats and they will look great. It seems that if you try to compress the schedule and not allow the first coats to cure adequately you can have issues that will follow you through the job.

From contributor Ro

i will try some sanding sealer from the same company. I have stayed with the same waterborne clear for 6 months and 10 gals i was hoping i would have it figured out