PDA

View Full Version : Enamel spraying with wagner HVLP















TomH
20th August 2010, 11:24 PM
Hi All,

I've got a bit of spray painting to do and have a Wagner 850E. I've never spray painted before so am unsure of what it is supposed to look like when I am putting it on.

I have some plantation shutters to paint. I first painted with oil based undercoat, full strength air and probably 50% paint. The finish was ok, but featured a fair bit of orange peel which sanded off ok. I then painted the first top coat (Dulux super enamel semi gloss). I thinned with turps to 10% as I figured the reason I got lots of orange peel was the paint was too thick. This coat was a bit disappointing. I found that the air flow was enough to cause rippling of the paint when applied. When I turned the air down it didn't look like enough paint was going on. I ended up with loads of drips, buut somewhat suprisingly after a bit of sanding and removing the drips with a chisel looks passable.

Tonight I painted a further set with the undercoat. Thinned by 10%. Turned the air right down and the flow right down then gradually increased the flow so I didn't get large drops. The finish is better than the first effort but is still fairly orange peely.

Questions for you all with similar HVLP guns:

1. What does a good coat look like when you are painting?
2. How light do you go (i.e. I could have moved the gun quite quickly and got bugger all paint on - but then I would be doing loads of coats)
3. Rough settings for using the Dulux super enamel - do you thin? how much air flow (i.e. min or max)? is the paint flow set up high or low.
4. How do you get the correct level of thinness in the paint - do you use a viscosity cup or just go by experience?

I realise with experience I will get much better, but any advice to speed the learning process would be appreciated.

Cheers,

Tom

TomH
21st August 2010, 12:15 AM
Since a picture is better than words I've taken some photos.

Some of the photos make it look pretty bad, as they are into the light, but it should give you a good idea as to what I'm talking about. The first three photos are with the thinned product, the second with straight.

Suggestions for improvement welcome. It is sprayed with Dulux 1 step oil based primer sealer undercoat.

acmegridley
21st August 2010, 10:07 AM
So thats what orange peel looks like!

Harry72
24th August 2010, 08:25 PM
You will always get bad orange peel effect with one of those type sprayers, oil based enamel doesnt like large amounts of air blowing on it while its flowing out... even with a standard spray gun you need to run as little air as possible(just enough to atomise the paint)and never go back over it.
Enamel will always have some degree of orange peel, this why cars used to be oven baked in the old days.(flows out for longer)

TomH
24th August 2010, 10:38 PM
Well, I took the plunge a did a final coat on one set of shutters. No thinning, reduced the paint flow to minimum but kept the air flow up high. Got some rippling when I applied but it leveled out and looks fine when dried. Still got some drips on the back side but the front side is ok.

The most challenging part is getting the slats evenly painted and not overpainting the sides when painting the slats. I guess this is why the kit I have bought for the next shutters advises to paint unassembled.

Any further advice most appreciated.