I Know SQUAT About Spraying Automotive Paint.

[Dan in Pasadena]

Hi Warrior!

Thanks for the advice everyone. I was gone for the weekend and the new switch arrived while I was gone. It's an eBay item, it was affordable but I have no idea if this is a good name part for these switches. But I t's a waay better quality part than the Harbor Freight item it'll replace. I just have to figure out how to hook it up - oughta be a cinch - and it ought to work fine.

EDIT: Oops, I went back and re-read. The other issues means I didn't say figured out why the unit wouldn't run? Yeah, I connected the wiring incorrectly! Once I fixed that I let it cycle three times up to 150 psi/down to 120 psi to turn back on. No issues that I detected other than I had to manually disconnect the power to make it shut off.

The original pressure switch is controlled by a cheesy plastic dial type "switch". When the plastic "hinge" on this cover cracked it no longer held the lid/switch thing in position to control the on/off.

[55dude]

take some time to understand the materials you think your going to use. materials are big bucks these days,start with the interior of your truck to get comfortable and to adjust equipment to your skill set. good luck!

[tinydb84]

Soda will leave an unknown ph on the steel. I would avoid using soda unless you are sure you know how to neutralize it.

Dan-when you say "go off' do you mean flash? You always want to paint the coats to whatever the P-sheet says. That being said I have rushed some coats without any negative effects but it was on stuff that I wasnt too concerned with (suspension parts).

I shot my firewall real quickly one night. I hate dealing with rust so after I finished filling it I hit it with a DA and shot it with Kirker epoxy. No body work, just welded up. I rushed the coats because it was late and I was tired but it came out fine. The spots on it are lint from the cover. It was done with a $20 no name Amazon.com detail hvlp gun:

[1project2many]

You just abraded away the surface with sand/glass and exposed the steel to the atmosphere. Why would you contaminate it with a chemical when it is already perfectly clean from the abrasive you just shot at it?

There is a technically sound reason for this. Iron exposed to oxygen and moisture will immediately begin to form iron(III)oxide, rust. Rust does not bond securely to the steel substrate, it provides no protection from the elements, and it is freely attacked by acids such as found in rain or humidity in the eastern part of the country. Phosphoric acid reacts with iron(III) to produce black iron phosphate. If phosphoric acid is applied soon after bare steel is exposed then a layer of iron phosphate will be formed. This layer will be bonded to the steel and will slow further formation of rust.

Now practically speaking, is it one more variable in the mix that can potentially cause problems? Definitely.

[OrrieG]

Originally Posted by Donaldo

Dan, be sure to put a water separator close to the compressor tank
Don

When I installed my air lines I was advised to run about 16 feet of line before the first water trap. The air coming out of the compressor is hot and water is in vapor form. The line allows the air to cool enough so the vapor becomes vapor and can be trapped. Also set up you tank so you can access the tank drain and get any water that accumulates in the tank when the air cools down. I run a second water filter at the gun.

I had not painted anything with a gun for 30 years. Primer is a good way to experiment with pressure, spray pattern, etc. most will be sanded off anyway. I found the modern paints to be very forgiving and have been pleased with the results. Nice thing is with BC/CC system minor problems are easily corrected without having to redo whole panels.

[Donaldo]

""When I installed my air lines I was advised to run about 16 feet of line before the first water trap""

That could be correct, I got an 80 gallon tank from the local tire shop when their compressor died) , put a 5hp v-twin unit on it, plumbing gets hot but never notice any heat on the tank, I piggy backed 2 small HF separators at the tank, no moisture in my paint.

[Dan in Pasadena]

Originally Posted by OrrieG

When I installed my air lines I was advised to run about 16 feet of line before the first water trap. The air coming out of the compressor is hot and water is in vapor form. The line allows the air to cool enough so the vapor becomes vapor and can be trapped. Also set up you tank so you can access the tank drain and get any water that accumulates in the tank when the air cools down. I run a second water filter at the gun.

I had not painted anything with a gun for 30 years. Primer is a good way to experiment with pressure, spray pattern, etc. most will be sanded off anyway. I found the modern paints to be very forgiving and have been pleased with the results. Nice thing is with BC/CC system minor problems are easily corrected without having to redo whole panels.

Ok, this info works well for my situation. My compressor is in the very front left corner of my garage. My 80+ yr old garage is only 18x18 so I'll run a line along the left side top of wall sloping down to the rear. I'll install a hose reel at waist height there with a water separator (or two!) right before the reel. Now the question is how to plumb that drop from ceiling height and catch the water BEFORE it can get into the reel? Hmmm, I'll have to think a bit about that. Yes, I know about putting one of those little water traps right before the gun.

[tinydb84]

I ran a couple vertical drops with black pipe off my compressor then back up to a water separator. I can run it pretty hard without getting water in my lines as long as I open up the valves and drain the water.

[_Ogre]

learn to shoot primer... so easy even an ogre can do it
shooting primer teaches you spray and mixing techniques
all primer will need sanding so don't worry about runs or overspray, but learn as you go so you don't get runs
you are correct in flash rust: sand blast, wipe down with wax and grease remover and spray primer.
asap

as mentioned the cooler your air the easier moisture will drop out
you can use a few 90*s and have 20 or 40 ft of copper tube taking up 2 ft of wall space
just be aware of where water will drain to and plan for it

[Dan in Pasadena]

Originally Posted by tinydb84

I ran a couple vertical drops with black pipe off my compressor then back up to a water separator. I can run it pretty hard without getting water in my lines as long as I open up the valves and drain the water.

Let me see If I can write what I THINK you and Ogre are telling me to do:

After I run my air up to a pipe that slopes to the garage back wall I'll turn the 90* corner then: R
- Run a drop the height of the wall AND GO BACK UP AGAIN before it goes to the water separator, is this what you're telling me?

- This gives the vapor 18 ft. to start cooling/condensing before it hits the up-down manifold. Walls are 8 ft. tall so it SEEMS like the 18 ft. followed by down & half way up again (to water separator/regulator - another12 ft.) makes 30 ft. before the separator. Am I naïve to think this is sufficient? I know dry air is better for painting and for blasting too.

I'll need to put a drain at the bottom of that run or even use multiple drops side-by-side - if you guys recommend it. But If I do the multiple drops I'd have to put a drain at the bottom of EACH run, wouldn't I?

Also, I don't intend to final paint the truck. I'd only be doing this primer to prevent the immediate rust. If I send it to a painter right after priming maybe I don't need epoxy primer? If he's going to work on it right away then do I need/not need the extra sealing an epoxy provides?

PS: I'd much prefer copper pipe but since my walls are already covered with painted OSB I'd probably use black iron pipe to avoid the fire danger. I COULD sweat up the "drop" manifold in copper on the floor then mount it to the wall, I guess. Just a bit more hassle. Opinions?

[Donaldo]

I'd put the water separator in between the compressor and your air lines - why have a hose reel full of water ? And it's suggested to drain the tank daily -

[Dan in Pasadena]

Originally Posted by Donaldo

I'd put the water separator in between the compressor and your air lines - why have a hose reel full of water ? And it's suggested to drain the tank daily -

Sorry, I didn't explain that well. I'd put the hose reel after the up/down runs and after the water separator/regulator. I want NO water in the hose reel.

Yes, I have always drained my tank after each use even the many years when I only had a cheap oil less 20 gallon compressor and even on my little Senco dual tank 5 gal. I use for a nail gun.

[Donaldo]

Drain the 'up/down runs' ? won't they eventually fill and the air flow push more water ? I learned the hard way, and I hate extra sanding when I shouldn't have to - so just sayin..........

[1958Warrior]

I think I follow you
Check out #16 in this thread I would recommend this placed before the hose reel, could reduce cost by using petcocks on the down pipe drains instead of ball valves. also would recommend 1' of drop below the T to the drains .

http://67-72chevytrucks.com/vboard/s...d.php?t=643549

But any of the various designs would help reduce water in the line.

[tinydb84]

Originally Posted by Donaldo

Drain the 'up/down runs' ? won't they eventually fill and the air flow push more water ? I learned the hard way, and I hate extra sanding when I shouldn't have to - so just sayin..........

They will fill but mine all have valves at the bottom of each drop that I drain before and after each day of use.

Originally Posted by 1958Warrior

I think I follow you
Check out #16 in this thread I would recommend this placed before the hose reel, could reduce cost by using petcocks on the down pipe drains instead of ball valves. also would recommend 1' of drop below the T to the drains .

http://67-72chevytrucks.com/vboard/s...d.php?t=643549

But any of the various designs would help reduce water in the line.

Mine is set up similar to post #13. If I do it again I will run them horizontally with one valve at the bottom.

[tinydb84]

This is mine. You cant see everything in the pic but I ran 3/4 black pipe up and down a few times with a valve at the bottom of each drop. I have a final air water separator at the top before the hose. When I am running the compressor hard you can feel the heat come off the pipe. I set up all the valves so I can reach them easily so I empty them often.

[_Ogre]

i prefer self draining cooling, so using 3/4'' copper tube and 90* fittings:

run horizontal 2 feet left, drop 2 inches, run back 2 feet right, drop 2 inches, run back 2 feet left, drop 2 inches, run back 2 feet right, drop 2 inches, run back 2 feet left, drop 2 inches, run back 2 feet right, drop 2 inches, run back 2 feet left, drop 2 inches, run back 2 feet right, drop 2 inches, run back 2 feet left, drop 2 inches, run back 2 feet right.

^^ this is 20 feet of copper taking up approx 2 feet by 20 inch space on your wall
for a 40 foot cooling loop repeat the above process
i suggest copper because it cools better and you could probably cut and solder a 40 foot cooler in one hour

on the bottom solder in a T, add a drop to the floor and put your low drain on the bottom and out of the other side of the T run up to your air lines
if you do a 40 foot cooling loop, you will not need a refrigerated air dryer

this is the best pic i could find of what i mean, it could be tighter and look better, but it works



air drop is a misnomer.

an air drop should come out of the top of the main header and then your air drop needs no drain valve
if your air drop comes out of the bottom it will fill full of water and will need a drain valve for every drop

this is a air drop

[tinydb84]

Orge posted how I will redo mine if I ever do

[_Ogre]

this will do the same thing, soft copper costs a bit more than hard line
make sure air goes in the top, water and air out the bottom
i have a roll of copper between my compressor and the tank similar to this

[Dan in Pasadena]

Originally Posted by _Ogre

this will do the same thing, soft copper costs a bit more than hard line
make sure air goes in the top, water and air out the bottom
i have a roll of copper between my compressor and the tank similar to this

Interesting and compact! I like that idea. How do you mount a coil on the wall? Where does the regulator and water separator go using that approach? Just put a single ball valve on the bottom of the coil?

[Dan in Pasadena]

Originally Posted by _Ogre

i prefer self draining cooling, so using 3/4'' copper tube and 90* fittings:

run horizontal 2 feet left, drop 2 inches, run back 2 feet right, drop 2 inches, run back 2 feet left, drop 2 inches, run back 2 feet right, drop 2 inches, run back 2 feet left, drop 2 inches, run back 2 feet right, drop 2 inches, run back 2 feet left, drop 2 inches, run back 2 feet right, drop 2 inches, run back 2 feet left, drop 2 inches, run back 2 feet right.

^^ this is 20 feet of copper taking up approx 2 feet by 20 inch space on your wall
for a 40 foot cooling loop repeat the above process
i suggest copper because it cools better and you could probably cut and solder a 40 foot cooler in one hour

on the bottom solder in a T, add a drop to the floor and put your low drain on the bottom and out of the other side of the T run up to your air lines
if you do a 40 foot cooling loop, you will not need a refrigerated air dryer

this is the best pic i could find of what i mean, it could be tighter and look better, but it works

What's interesting to me about this is the possibility of mounting it overhead to my exposed rafters rather than the wall. My garage is only 18x18 so wall space is precious. Mounted to the rafters it would obviously be sloped downward and I could put as many turns in it as copper I can afford!
Just thinking out loud, not sure I'd do that but it's an idea!

[tmoble]

>> "It has become a FRAME OFF RODSTORATION!!!"

LOL, what did you think was going to happen?

[Dan in Pasadena]

Originally Posted by tmoble

>> "It has become a FRAME OFF RODSTORATION!!!"

LOL, what did you think was going to happen?

Thought I was going to pull the front clip & engine, install the ifs and button it back up. But you see, there were beers......

[tinydb84]

You can also use an AC condenser between the compressor and the air/water separator.

[1project2many]

                   _________________
                 |                    |
                 |                    |
                 |                    |-----Air hose
 Compressor______|                    |
                 | Trap drain         | Trap Drain

Around here we deal with high humidity so water is an issue. Here's a preferred routing. Run the pipes high after a vertical rise from the compressor. High horizontal supply line should be sloped some away from compressor. Drop individual tap lines down from horizontal supply line to air hose connection at 36" or so. Continue vertical drop for 24-30" below the air fitting and place drain valve. This drop acts as a trap for liquid water -n- oil that comes from compressor. A similar trap is often placed just after the compressor on the vertical rise to capture any water draining back as air cools after compressor shutoff. Filters / dryers are also used at each air hose connection point.