confused about HVLP gun pressure

[the snooper]

you just need to get to grips with the gun that's all, make sure you have the correct amount of thinner in the paint then play with various settings until you get to grips with it

 

[langy]

When i'm using my HVLP guns I just set the wall reg to 40psi and then fine tune at the gun, I can't understand why you are having so much trouble

 

[Daz1968]

I use a devilbiss, and the regulator is set at 75psi mainly so I have enough pressure for the mask, the gun take off has a small regulator mounted just before the gun and I open the gun trigger and just adjust this small gauge to show 2bar, can't see how anything could work different.

 

[brightspark]

When i'm using my HVLP guns I just set the wall reg to 40psi and then fine tune at the gun, I can't understand why you are having so much trouble

i do the same if i set the pressure say to 45 psi out of the tank thats it i think what people are trying to do is get 45 psi with trigger pulled and think it will maintain that pressure ??? its bound to drop

 

[the snooper]

is the regulator he has able to supply enough CFM ?

 

[eil]

What length and bore is your air hose, what kind of fittings do you use.

 

[carl0s]

i do the same if i set the pressure say to 45 psi out of the tank thats it i think what people are trying to do is get 45 psi with trigger pulled and think it will maintain that pressure ??? its bound to drop

Precisely, but this is what everybody is telling me to do, and I'm saying it makes no sense!

 

[carl0s]

What length and bore is your air hose, what kind of fittings do you use.

100ltr tank. 15mm copper pipe, various drip legs, 1/2" BSP regulator, then into a 9mtr 1/4" hose reel, into the gun which has a mini diaphragm regulator on it.

 

[eil]

I would change to a 3/8 or 10mm airline straight away, are you using an air fed mask as well.
Oh and not on a reel.

 

[Daz1968]

1/4 hose is a bit small, I use 3/8 for air tools and 5/16 for painting, mainly because 5/16 is dia of my breathing hose, you also need good high flow fittings

 

[carl0s]

Anyway

I would change to a 3/8 or 10mm airline straight away, are you using an air fed mask as well.
Oh and not on a reel.

Not from the same air lines no.

 

[carl0s]

but all the hose reels are 1/4, and the gun is 1/4 ?

let me go and confirm what I have.

 

[carl0s]

It's 8mm bore hose.

The fittings are machine mart P-whatsit (quick-disconnect)

 

[brightspark]

its not a good idea to use hose reels as u get a build up of water in them hoses are best left layed out flat and strait i use 10mm bore near enough to the job and use 1/4 bore the last few meters to the gun as the 10mm is 2 stiff using the gun

 

[eil]

Get yourself a 10m x 10mm airline they aren't expensive, you will notice the difference, what you're getting now is cranking up the pressure that it blasts out when triggering and then dropping off, giving you uneven paint flow as well could be pushing your hand back on triggering meaning you might well not being able to keep your distance from the panel consistent.

 

[carl0s]

OK. I thought it'd be a pain, but I can quick-connect at the wall regulator...

I'll give it a try. I'll get some bigger hose.

Thanks :-)

Here's what the set up looks like, except that I have added a coil in a bucket of water right after the compressor tank now (to put ice in... )

I'm hoping any water would be caught in the drip legs.

 

[carl0s]

I might try removing my copper-coil bucket of water thing too. It's only 10mm copper pipe.

 

[the snooper]

if you have the air passing through a coil in water and it does condense the water then eventually it will build up and a load of water will be fed into the gun

 

[carl0s]

It should get caught in the drops though, no?

Looks like this:

(it needs a tap fitting for emptying)

 

[carl0s]

**** i didn't see that big spider when I was there