first try at hvlp spraying

oops---just finished one coat of primer and one coat of oil base sherman williams pro series paint on a nice kitchen island project i built for my wife out of poplar. its first class construction complete with raised panel doors, legs turned on my lathe, oak dovetailed drawers. but my finish was suppose to be buttery white semigloss. it has little bumps of paint--yuck.

I sanded out the primer coat, touched it up and moved on to the first coat of paint. i thinned the paint with paint thinner, but still got the bumps. I don't know if i would call it orange peel--its more like small globs of paint coming out of the hvlp. i have tried pressures from 20 to 60 and tried to vary the amount of paint and spray pattern.

it is running around 45 to 60 degrees in my shop so i may have to wait until it warms up.

does anyone have any ideas?

thanks,
ernie riley

Ernie,
Besides being too cold in the shop to spray paint. Did you filter the paint as you were pouring it into the cup? The other problem culd be that you have the atomization set incorrectly causing material to dry on the air horn and causing the dry spray.

Gary

You may also need to get a bigger needle/tip. What type of paint is it? If it is water based, you may need to thin up to 50 percent with floetrol.

What kind of gun are you using, and tip size? I would not spray in temps less than 70 degrees, and no higher than 85. I know how it feels though. Wait until it dries, sand smooth and recoat with a slightly less viscous mix. I would try some of the waterborne finishes out there instead of the oils. The waterborne "lacquers" would allow you some flexibility on the temp range, but you should still try to warm it up where you are spraying. Regards, Bill

:) i appreciate all the kind hints on my spraying woes. i am using a craftsman hvlp spray gun from sears. the paint is an oil-base from sherman-williams. i am filtering the paint and trying to thin it with paint thinner (not sure what i'm doing). i checked at sears today, but no one knew anything about getting a different needle/tip set up.

i agree that i either need to heat my shop or wait for better weather.

again, thanks, i'll give you an update after my next try.

ernie riley

Ernie,

The spray cap and needle that come "standard" on most guns are sized for thinner materials for spraying. Even with my AccuSpray HVLP setup, it requires a larger spray cap and needle to spray heavier finishes like paint. As you thin your paint for spraying, remember to add in some flow-out improver in the mix as well. Floetrol is one that you can add to the paint and is normally available at Lowe's or Home Depot. Read the directions on the can carefully because it won't be nice if you add to much to your mix.

Warmer temps in the shop as well as warmer "finish in the can" can be of benefit as well. If you are spraying in a cooler shop, leave the finish in a warm area of your home and bring it in the shop when ready for mixing and spraying. This "can" help with the flow, but I'm thinking that your shop and finish are too cold to spray properly without thinning way too much to spray well.

Dennis, he said he's spraying oil-based paint--he'd pull his hair out if he used Floetrol. That's for waterborne products. Penetrol is for oil-based.

Ernie, what are you using for paint thinner? If you're just using the cheap stuff that's about $3/gallon, don't. Upgrade to the stuff that's closer to $10/gallon or $5/qt (low-odor, usually), or use VM&P Naptha. Without actually seeing what the "orange peel" looks like and your setup, it's hard to diagnose because there are many parameters that can cause a less-than-smooth surface, some of them extreme opposites but causing the same result.

Which Sherwin product (name) are you using? I may be familiar with it.

Ernie
I'm going through the same problem, first time w/HVLP using S/W oil based paint. Spray booth is in the 60's and at first I had the ruff texture. I kept thinning until the paint mixture look almost like water, it work at lot better. I am using wagner HVLP conversion gun w/ #3 tip probably should be using #4. I'm not sure if I'm supposed to be thinning it down that much but the finish came out nice once I thinned it down.
Brian

Quote:

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Originally Posted by Jason Roehl

Dennis, he said he's spraying oil-based paint--he'd pull his hair out if he used Floetrol. That's for waterborne products. Penetrol is for oil-based.

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You are correct sir and I stand corrected. :D

I knew it was one of those "trol" things. ;)

Quote:

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Originally Posted by Dennis Peacock

I knew it was one of those "trol" things. ;)

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Now you're just picking on me. :D