WB Urathane Spray Problem

[JGS]

I have been using my Turbinaire HVLP sprayer for about 8 months now and have been quite happy with the results. However, I have been trying to use Fuhr WB urethane on a table top with less than good results. I was getting large bubbles trapped in the finish. I called the supplier and subsequently applied half as much per coat and used more air. This gave a definite improvement but now I have small bubbles trapped in the surface. The RH in the shop is about 30% and temperature is about 20 (68*). I have used it straight and diluted about 10% with water giving what I think are the same results. So, any ideas on how to get rid of the bubbles? Thanks, JG

[Rumpty]

It sounds like you are laying on too thick a coat.

[Rumpty]

Question, how much are you stirring prior to application? Also, is your finish the same temperature as the work piece and surrounding air/workspace?

Rumpty

Radial Arm Saw Forum:

- - - - - - - - - - - - - - - - - - - -

[Mike G]

Several but they would all entail being with you to see what exactly is happening. Since we can't do that I'd suggest contacting the maker and seeing if they have or can recommend a retarder to increase the time the bubbles have to work themselves out of the finish.

[Bay Area Dave]

don't know about that brand, but the WB urethane I use, (Enduro) is reduced with a flow modifier; NOT water...YMMV. It is useful for both cold and warm spraying environments. I haven't used it a lot, but what I have sprayed has ZERO bubbles in the finish (mid 60's temps and humidity around 75%)

dave

JGS wrote:

[Bay Area Dave]

just realized I implied I haven't used the flow modifier much; what I meant was I haven't sprayed MANY projects, but those that I did spray, I used the flow modifier each time, with GREAT results.

dave

Bay Area Dave wrote:

[Rumpty]

Dave,

Hydrocote used "flow modifiers" 15 years ago with their products. These days you don't need them with Hydrocote products, and their Hydrocote Resistane sprays just like a traditional lacquer. You really need to try a good WB product..

;-)

[Bay Area Dave]

Are you implying that Enduro is junk?

dave

Rumpty wrote:

[JGS]

[JGS]

[Rumpty]

If you the consumer has to fiddle and add retarder, yes. In it's early days Hydrocote had to use retarders too, that hasn't been needed in 15 years. Someone here is behind the times in technology. I shoot Hydrocote Resistane every week and I shoot under some pretty lousy conditions at times and the stuff performs.

Why should you have to be the chemist???????

Get with the program Dave! ;-)

[Bay Area Dave]

Just call me a throw-back; I'll stick with the Enduro, thank you very much! :)

dave

Rumpty wrote:

[Rumpty]

particular can settles out quite quickly so I have to stir it and use it within a few minutes. JG

I opened a new gallon of Hydrocote Resistane satin that was made in 4/03 so it really needed to be stirred. I had a bunch of bubbles stirred in. Upon application the Resistane flattened out fine with no bubbles trapped.

Two suggestions, they had a bad mix with the gallon you are using, OR your gun is dirty and causing a problem. The WB product takes extra effort to keep the gun clean.