do you set psi at the gun with or without paint loaded

[jcbadger]

Hi all

This is the first time I've sprayed. I have a reg fitted at the gun which should be set at 35psi when fully triggered. My question is do you fill the gun with paint then set the psi? I set it BEFORE I filled it up with primer. When I pulled the trigger back with primer in the gun the psi, when triggered, dropped to around 20psi (i was spraying thick epoxy primer). Did the psi drop from the 35psi setting (before I filled up the gun with primer) to 20psi because of the thickness of the primer being sprayed? thanks

johnny

 

[Drains]

Johnny, set it with or without the paint loaded, and the trigger NOT pulled.

 

[Chipper]

Must be HVLP though, to be at 35psi though which seems always given as pressure at the air cap, i.e. trigger pulled. Is this the very first try then or have you used this gun before, with other paint? That's a great big pressure drop there.

 

[piman]

Hello Drains,

Surely the pressure at the gun is with the trigger pulled, as there can be a significant drop if adjusted with a dead end. That's how I do it anyway.

I don't see how the pressure at the gun can vary whether it is loaded or not unless the paint needle and fan is adjusted after fillling (As you would) so altering the air demand,the other factor is the length of hose and it's size?

Alec

 

[eil]

Set the pressure with the trigger pulled fully back, with your air fed mask connected if you are using one with the same air line. adjust the pressure at the wall reg first then fine tune on the gun.

 

[Engineer]

Unless you have something like a Sata reg, the gun mounted ones are not likely to be that accurate. Fast and easy way to set pressure is to simply try spraying a test piece with whatever material you are using and if you are not getting good atomisation, then gradually increase pressure until you do.

 

[Chipper]

Johnny
If you were adjusting your reg downwards to 35 from some higher pressure, give the trigger a quick pull, there can be quite a drop then. Re-adjust to 35, should then be stable. I.e. the dead end as Alec mentions. Hopefully this is all it is.

 

[jcbadger]

thanks for the replies. The reg could be dodgy - its a very cheap one off ebay and air seems to pass through the adjusting knob when opened up. I'll give it another try or bin the reg and get another one. can anyone recommend a good one but not an expensive one - this is just a hobby. They all seem to be pretty
generic and non-branded on ebay. thanks

 

[REDBURN]

Setup

I found this vid very helpful,

http://www.youtube.com/watch?v=HU6bh5mNbyA

especially after i blew the air cap gasket!

 

[leeruddock]

best way i find is get a piece of card or paper spray a sample on it untill you get the right spray pattern ie no orange peel etc. as for the regulator at the gun i never use one i just use the reg at the point you connect your air hose. hope this helps?

cheers
lee