Spray Painting for the complete novice

[rhamer]

As my loader project gets closer to completion, I'm now starting to think about how to paint it.

In the past the only spray painting I've ever done is out of a can, so using a compressor and spray gun is completely new to me.

The equipment I have is a small compressor (about 90PSI) and a spray gun that came with the kit that has the pot underneath.

I have no idea how to use the gun, or how to set it up for pressure, pattern etc.

Any advice at all on every step would be most welcome, including preperation and undercoating.

I'm not looking to become a custom car quality painter, but I would like to be able to produce a reasonable shiny finish.

Cheers

Rohan

 

[Gary Fowler]

Before you paint, you are going to have to rough up the surface and clean off all the oils, rust, dirt, etc. The best way is sandblasting but you could do it with a stiff bristle wire wheel on a grinder and then wipe it down with acetone to remove the grease. I found my gun to work best at about 40 psi. You will just have to experiment with the paint flow needle valve to get the right amount of paint. Might try it on some cardboard or something to get it set right. You will need something to filter the air from your compressor so you dont get water into your air supply cause if you do, you will see little beads of water forming on the painted surface and that will leave little holes in your paint. I think that you should be able to get a shiny coat on with the little cheap gun, but dont expect automotive quality. Surface prep is the most important thing and probably 90% of the road to sucess is getting the prep right. The rest is setting the gun and keeping it right distance and moving it right speed in other words experienced spray painting. Start with the bucket first as that paint will get worn off anyway with use. By the time you get the inside of the bucket painted you should had it set fairly well. Also you will likely have to thin the paint so talk to you paint supplier about that as it has to be just right to spray with that gun.. Too much thinner and it will run on you and not enough and it wont spray right.

 

[bobodu]

Google "spray gun tips" and "spray gun help". Far too many good links to add here.Good luck.

 

[allenr]

You don't need a lot of pressure or flow for spray painting - your compressor will be more than adequate.
I don't use a pressure regulator, just full pressure but reduce the air flow with the little knob down near the coupling. Fully in will be no air - never use it fully out if you don't have the seperate regulator.

There'll be at least one knob above the V foomed by your thumb and forefinger, the correct one will adjust how far the trigger will pull in thus adjusting the amount of paint let through by the trigger. If memory serves me it's, once again, fully in = little or no paint.

If there is a second knob there, or it may be on one side by the nozzle, that one will adjust air flow to the protrusions by the nozzle, which in turn adjust how wide the paint will spray. (the little air holes in the protrusions love to get clogged with paint)

Sandblasting prior to painting is always the ideal, but if there is little or no rust, spatter or mill scale you may get away with going straight to a primer.

Your pics in an earlier post showed a fairly glossy (smooth) mill finish to the RHS - in that case I'd use Wattyl Super Etch Primer, it adheres well to any surface, goes on smoothly with little powdering even in hot weather and the final coat will adhere well to the Super Etch.
Probably not quite as good as a cold galv (zinc rich) primer, but very close and much easier to apply.

Super Etch is difficult to clean from a gun with turps or even petrol - a 100% Hydrocarbon thiner is the go for thinning (in hot weather) and cleaning.

As for top coat I'll normally go for a 1 pack Wattyl or Solver Enamel.
Leftover, unmixed 2 packs will still dry out over time so I don't think they have much benefit over normal enamels.

I usually put leftover enamel in a smaller tin or glass jar with good lid seal - it needs to have little or no air space.

Has anybody ever tried refridgerating or freezing leftover paint - in it's original tin to prevent drying out?
My wife won't let me try!

 

[EddieWalker]

After you read the basics and get it all together, you can do your experimenting with the primer. It's more forgiving and will allow you to get a feel for how your spray gun works. If you over do it and get a run, no big deal. You just sand the primer smooth after it dries. Since this is a loader, the level of skill required isn't as critical as just getting paint on it to protect it from rust.

Be sure to do it in an area where you don't have to worry about overspray. If doing it outdoors, pay attention to the wind and what is downwind of what you are spraying. There are too many cars/trucks out there with little dots of paint on them from the wind!!!!

Enjoy, painting it should be the fun part.

Eddie

 

[Squeak n Itch]

Virtually all spray guns produce output in a cone shape. Then, jets at the side of the outlet "push" that cone into what they call a fan shape, either vertical or horizontal depending on how you set the "wings" on the front of the nozzle. Play with the amount of air diverted to these wings and their position. Spray against a piece of cardboard. Even the pros use trial and error to set the gun up the first time. Jump in and don't forget the three rules for using a spray gun - clean it afterward - repeat - repeat.

Have fun! It is like golf - either you will love it and want to continue until you are pretty good or it will become a PITA that HAS to be done from time-to-time.

 

[Squeak n Itch]

Has anybody ever tried refridgerating or freezing leftover paint - in it's original tin to prevent drying out?
My wife won't let me try!

IMO
Almost all latex or water base paints become unstable when frozen. The suspended particles of pigment and binder tend to clump up or agglomerate and the stuff becomes pretty much useless.

 

[Wheatland KB]

The paint / thinner ratio is important so talk about it with the supplier and follow the instructions on the can. The instructions should also give a pressure setting to use so a filter and regulator give the best result. You will get good practice with the primer coat and as was stated in an earlier post you can sand imperfections from the primer before shooting the color. Most paints that I've used ask for a "flash Coat" to be applied directly over the primer. This is a quick, thin coat that you allow to flash, which just means let it tack up for (if memory serves) 1/2 hour or so and allow the thinner to evaporate. The next coat(s) are put on a bit thicker but not so thick that they run. The thicker coats need more flash time and you can also wet sand any imperfections between coats if the paint is dry enough.
Find out the flash time, pressure setting and mixing instructions for both the primer and paint from either the instructions on the can, the supplier or the manufacturer. Practice on a piece of cardboard first, be patient and have fun. I'm sure it will look great

KB

 

[Soundguy]

If it's a little syphon gun, it will be easy to use.. only downside is they are air volume hungry.. and throw a little more overspray than pressure guns or hvlp.

your 90psi is fine.. the more gallons of air storage the better.

mixing your reducer and paint will be the biggest deal to learn to make the gun happy.

have a piece of scrap metal to paint on. the gun likely came with a manual.. showing pattern adjustments at the front and mix knobs .. usually on the rear... depending onthe gun design.

soundguy

As my loader project gets closer to completion, I'm now starting to think about how to paint it.

In the past the only spray painting I've ever done is out of a can, so using a compressor and spray gun is completely new to me.

The equipment I have is a small compressor (about 90PSI) and a spray gun that came with the kit that has the pot underneath.

I have no idea how to use the gun, or how to set it up for pressure, pattern etc.

Any advice at all on every step would be most welcome, including preperation and undercoating.

I'm not looking to become a custom car quality painter, but I would like to be able to produce a reasonable shiny finish.

Cheers

Rohan

 

[rhamer]

Thanks guys, this is great stuff.

What about types of paint?

I know there are oil based and water based (known by various names like enamel? and acrylic?) I would think that oil based paint would be the go for steel? or is it only the undercoat that matters? From my little painting experience, in order to get a gloss, you need to use oil based, right?

Also I was just going to go to my local Bunnings (mega lo mart) and get them to mix up the colour I want. Will that work, or should I go to a dedicated paint place?

And lastly, how do you clean the gun both between colours and when finished.

Cheers

Rohan