Topic: Paint / air compressor question

[Johnny5]

Dont know if this is the right spot to post this, but since Im preparing to paint my SOHC bike, I guess it's okay.

So, I got some auto paint/reducer/hardener at a paint shop. I picked up a small paint gun at Harbor Freight and the manual says the gun operates within the range of 20-50psi and consumes 3cfm at 50psi. Do not exceed 50psi.

So my question is, do I set the air compressor to around 30-40 to start with? Or are the psi adjustments made at the gun? I dont really understand the cfm at certain psi's. Any info on this would help me understand a little better. Im really new to painting.

Thanks,

[mystic_1]

For example, a garden hose without a nozzle will deliver a high volume (cfm, Cubic Feet per Minute) of water, but a low pressure (psi, Pounds per Square Inch).  A squirt gun, by contrast, delivers low volume but at high pressure.


As far as your compressor is concerned, set the compressor's regulator higher than 50psi, then use the regulator at the gun to set the final pressure.  If you have a smaller compressor, then you'll need to pause every now and then to let the compressor catch up.  Start out with lower gun pressure (say 25) and do some test sprays on scrap to set up your pressures and spray pattern.  Most common mistake (speaking from experience) is to spray at too high pressure, or too close to surface, resulting in too thick of an application which can lead to runs.

Finally, most of the work in paint is in the prep, so prime and block-sand until it's perfect.

mystic_1

[Johnny5]

Thanks Mystic.

Yeah, Im all ready to go with my tank and sidecovers, but Im not going to paint them until I have practiced a bit. Thanks for the info. Im going to give it a go tomorrow. I need to pick up a regulator and water filter.

[Tattoo]

I totally agree. One thing I will say if the paint your spraying is high metallic you will need more air pressure. Tattoo

[moham]

Does it matter at all if its an HVLP (high volume low pressure) gun? With HVLP there is supposed to be less over-spray reducing the amount of particulate in the air. For the HVLP guns I've seen, they generally require a decent size compressor to keep from having to run so much, ensuring a more consistent final spray (I guess that would be the case for either type of applicator). Just a thought as I was contemplating the garden hose comparison. 

[Tattoo]

I've always found with high metallic paint it doesn't matter what type of gun you use if you don't want streaks of metallic you need to jack up the pressure a little. Now I don't mean 20Lbs 5 or so. Tattoo

[Johnny5]

Good tip about adding a little pressure. The paint I got was silver metallic. From what I hear, not the easiest paint to lay down. I suppose if I learn with this paint, I'll be able to lay down anything...

[Tattoo]

Is the silver like the 80s Honda F Silver or is it like the 70s bigger flakes? Tattoo

[Johnny5]

It's 2003-04 Dodge Bright Silver. Has super small flakes in it.

[Tattoo]

That won't be that bad. Just don't get the gun to close or it will streak. Good luck, Tattoo