how to set up spray gun

Currently reading:
how to set up spray gun

Joined
Aug 10, 2003
Messages
125,246
Points
24,395
Location
Essex/Suffolk border
got me a new one today from reduced corner of machinemart,
http://www.machinemart.co.uk/shop/p...ath/spray-guns-spraying-equipment-air-brushes

000510095.jpg


save me messing about trying to remember what all the knobs should be turned to does some one want to roughly tell me?

stuff on the net say things like (set the regulator on the gun handle to 50 psi (what I use for DP40 and K36) with the trigger pulled and leave it set there. Close the valve at the bottom of the handle (on the gun, not the regulator) and then with the trigger pulled, open it to the point where the air volume starts to stay the same (just listen to it) and leave it there (it should be pretty far open at this point). I never mess with this after this unless I think it has been changed.)

so some thing a bit easier to understand please :)

oh am spraying bumpers with 2k
 
Last edited:
OK, well I find it confusing enough because in the photo, you don't appear to have a pressure regulator built-in to the gun (if you did, it would be at the bottom of the handle). You need to add this in the supply - either as a regulator on the compressor, or as a combined filter/regulator (better).

The knob on the side sets the fan size. It alters the air going to the air cap horns. If you turn this clockwise you get a small circle, and if you turn it anticlockwise, you get a large oval.

The knob on the back sets the amount of paint. The further 'out' (anti-clockwise), the further the needle gets pulled back when you pull the trigger. Basically, it acts as a stop for the trigger and prevents you accidentally squeezing it too far (and getting too much paint).

This is how I would proceed:
1. Set pressure regulator to 40psi (on compressor or on in-line filter/regulator)
2. Set fan size to 2/3rds of maximum
3. Adjust air pressure up or down to find minimum pressure that still atomises paint finely. The edges of the spray fan should be soft, not splattery.
4. Adjust paint volume so that centre of fan has desired amount of paint. Test-spray onto cardboard, reduce paint volume if runs are unavoidable.

If you are doing detail work, turn the fan size down. Generally you need the pressure as low as possible because otherwise you may ripple the paint if spraying close-up. Plus, having low pressure reduces paint mist blown everywhere.

-Alex

got me a new one today from reduced corner of machinemart,
http://www.machinemart.co.uk/shop/p...ath/spray-guns-spraying-equipment-air-brushes

000510095.jpg


save me messing about trying to remember what all the knobs should be turned to does some one want to roughly tell me?

stuff on the net say things like (set the regulator on the gun handle to 50 psi (what I use for DP40 and K36) with the trigger pulled and leave it set there. Close the valve at the bottom of the handle (on the gun, not the regulator) and then with the trigger pulled, open it to the point where the air volume starts to stay the same (just listen to it) and leave it there (it should be pretty far open at this point). I never mess with this after this unless I think it has been changed.)

so some thing a bit easier to understand please :)

oh am spraying bumpers with 2k
 
Last edited:
A very good informative answer up above (y)
If I just add.

For starters invest in something like this and mount it close to the gun.
this is just an example,
http://cgi.ebay.co.uk/SMART-REPAIR-...ryZ30923QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

The reason being, if you have a gauge on the compressor by the time the air gets through the hose you loose psi. as a result you can end up spraying at too low a pressure.
On a hvlp gun I usually spray a triggered pressure, as in the gun trigger pulled back (registered at the gun) showing 29psi 2 bar on the gauge. Although as above my guns have a regulator on the bottom of the handle

Make a note of the original settings. Have a few test sprays altering each knob and take note of the different effects. :)
 
This post contains affiliate links which may earn a commission at no additional cost to you.
hmmmmm, dave it would appear the tub needs a new wing......or two, fancy trying your new found skills out on them?

of course i doubt you could replicate the runs, paint brush, orange peel under paint bird **** effect....but you could try:D
 
no a pic of my gun is up there ^

found out why yesterday didn't go right, stupid paint shop changed tins, white square tine used to be 2k thinners, now its single lacquer so i thinned primer with lacquer :bang: and cleaned gun with it, lucky i cleaned gun after with cellulose thinners so it not bunged up.
other man served me today and said he had no idea why other bloke had even sold me single lacquer when i had 2k primer an base coat
 
no a pic of my gun is up there ^

found out why yesterday didn't go right, stupid paint shop changed tins, white square tine used to be 2k thinners, now its single lacquer so i thinned primer with lacquer :bang: and cleaned gun with it, lucky i cleaned gun after with cellulose thinners so it not bunged up.
other man served me today and said he had no idea why other bloke had even sold me single lacquer when i had 2k primer an base coat

Hmmmm.
I think I understand that there would be a problem with that! But there's a lot of terms in there :)

To recap terms, there are two types of paint - lacquer (dries by evaporation) and enamel (dries by hardening).

Lacquer paint - also called Acrylic Lacquer - seems to be what you folks call Cellulose. I don't use it.
No-one here has 'lacquer' thinner.
We have 'Universal' thinner (does both lacquer and enamel).
2K primer needs universal OR 2K thinners (the latter is technically called 'Reducer' rather than thinners, for some reason).
2K basecoat isn't 2K - it's technically a lacquer, as it has no hardener and dries by evaporation. Either thinner would work for this.
2K topcoat or clearcoat (acrylic enamel) ideally needs 2K thinners ('slow', for best gloss/flow-out) rather than Universal.
I always use universal thinners for cleaning-up.

Re-reading, I think I see why I was confused. :rolleyes: People in England seem to use the term 'Lacquer' interchangeably with 'clearcoat'. This is confusing because when we use the term 'Lacquer', we mean paint that dries by evaporation, i.e. what you would call Cellulose.

So I guess what you're saying is that you poured clearcoat into the gun to clean it!

I did something similarly hopeless once when I accidentally used unlabelled hardener as thinners. I'm sure that was really good for my isocyanate exposure. :bang:

Anyway, let us know how you get on with the proper thinners - should be about 10% for 2K paint or primer.

-Alex
 
Now i'm confsed Alex :D

Our old paint type was cellulose.

*Primer
*Cellulose base coat.

The cellulose has a shiny finish which once sprayed is sanded/polished.


2k paint

*2k Primer, mixed with a hardener.
*2k base (colourcoat), mixed with a hardener
*2k clear coat (lacquer) mixed with a hardener

Thinning of each paint is to allow better flow through the gun. I dont spray 2k base coat but I usually thin the primer by 10-15% although all products vary.
I don't thin my lacquer but some need again 10% to allow better flow and thus prevents orange peel.

1k paint

* primer mixed with thinners
* base (colour coat) mixed with 50% thinners
* clear coat (lacquer) used neat or with 10-15% thinners

1k paint is less toxic than 2k. The clear coat lacquer is weak and requies more finishing with an inferior shine to 2k. I usually spray 2k lacquer instead over the 1k base coat.

Water base.

*2k primer, although a water based primer is on the market
* waterbase base coat. pre mixed. or if not then mixed with 15% distilled water or 20% special water thinners.
*2k clear coat however 1k can be used as well. A water base lacquer is soon or possibly on the market.

Water base is great. Is just like emulsion. Do not believe the bull, as it is easy to spray and only requires a hair drier to dry panels fast. remember the water is just to thin the paint. once dry it has all evaporated off.
 
Last edited:
Back
Top