Thread: Garage Painting for Dummies

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Originally Posted by IC2

Depends on the gun air flow requirements(psig and capacity in SCFM) and the SCFM of the compressor at the rated flow of the gun. If you are using a Harbor Freight 'purple' 43430 gun, no. If you are using an Iwata LPH400 series, yes. DeVillbiss Finishline 3, yes. Sharp. yes

I have a 5hp campfeld hausfeld compressor(can't get to it to see the cfi), and a set of new Devil Bliss(starting line) guns, I bought last year from Summit on sale.

Originally Posted by stovens

I have a 5hp campfeld hausfeld compressor(can't get to it to see the cfi), and a set of new Devil Bliss(starting line) guns, I bought last year from Summit on sale.

Steve,
I also have a campbell hausfeld compressor that says it is 5hp atop a 20gallon tank, but the scfm is only 6.5 at 40psig, and 4.5 at 90psig. I now have a 3hp unit on a 60 gallon tank that drives a compressor that flows 13.5scfm at 40, 11.5 scfm at 90. There are two major problems with trying to scrape by with a small compressor, as I understand it - 1) heat due to the duty cycle on the compressor fills the tank with very hot air, and hot air has more capacity for entrained water which tends to precipitate out in the lines; and 2) heat due to the duty cycle can cause the compressor to blow a little oil into the air, and any amount of oil is going to fish eye your paint. If you "can't get to it to see the (flow)" does that mean you have it buried in a hole where it does not have lots of free air flow? That is another strike against a lower than ideal compressor - lack of free air drives up the heat even quicker. Not trying to rain on your parade, but air volume is king, and your compressor should not see more than a 50% duty cycle while spraying, to keep as cool as possible.

Roger my compressor is 30 gallons, but not sure on the rest of the specs. I',m incline to shoot some base color on the inside of the cab, before taking it to a pro to do the outside. Who knows it may stay primer gray for a few years just to hide all my mistakes!

Originally Posted by stovens

Roger my compressor is 30 gallons, but not sure on the rest of the specs. I',m incline to shoot some base color on the inside of the cab, before taking it to a pro to do the outside. Who knows it may stay primer gray for a few years just to hide all my mistakes!

Steve,
I hear you. They can put any size compressor atop any size tank, so tank volume really doesn't tell you much. The key is volume flow capacity on the compressor, because once you start using air and you reach your lower set point (usually around 80psig?) if your usage rate is at or exceeding your compressor capacity your compressor will run continuously trying to keep up, until you stop using air - it will never get up to the upper set point (may be 125psig, 150psig, or higher). More tank volume will delay the start of the compressor, but once it starts it may not shut off again. In fact, if you daisy chain several tanks together once your compressor starts you now have a massive volume of air you are trying to make up (to get all of those tanks back to your "compressor off" set point).
So far I have spent about $1000 on getting an area of the barn set up to paint, and it is in no way a pro paint booth. For me, it is a matter of liking to do things myself, and learning as I go. I love the challenge of tackling new things related to the build, and I don't plan to ever be at a formal "car show" where a $10K+ paint job is the expectation.

Roger I'm with you. I have no where near the skills to do show car quality, let alone quality!
I would like the paint to look nice though, just tormenting over self learning curve vs. big bucks shop finish!
I'm off tomorrow so I'll clear out the corner the compressor is in and check out the specs!

Is there a preference for setting up your intake and exhaust ? Should they both be low to the ground or the intake higher and the exhaust low to the floor. I was thinking about my power roof ventilator that I have. Couldn't I duct that into the shop at floor level and put a filter box on it and use it as my exhaust. Then do a filter set up from under the garage door for intake as rspears post suggested. Intake on one end of booth and exhaust on the other end.

Originally Posted by stovens

Roger I'm with you. I have no where near the skills to do show car quality, let alone quality!
I would like the paint to look nice though, just tormenting over self learning curve vs. big bucks shop finish!
I'm off tomorrow so I'll clear out the corner the compressor is in and check out the specs!

Steve, I'd give it a shot. I figure every good painter who ever painted had to start somewhere, plus we've seen a lot of testimonies here that nice jobs can be done in garages. I've done 5 cars now, each has gotten progessively better, and i learn a little more each time. You can do it, brother!

Originally Posted by buzz4041

Is there a preference for setting up your intake and exhaust ? Should they both be low to the ground or the intake higher and the exhaust low to the floor. I was thinking about my power roof ventilator that I have. Couldn't I duct that into the shop at floor level and put a filter box on it and use it as my exhaust. Then do a filter set up from under the garage door for intake as rspears post suggested. Intake on one end of booth and exhaust on the other end.

Take a lesson from the pros. If you did a search for paint booths you'd notice that whatever style they almost always exhaust low. Old tech (and cheaper) is cross flow where it comes in the back leaves the front. The ultimate is what's called a down draft where the ceiling is the filtered intake air, and the floor is set over a plenum for filtered exhaust. The less "sophisticated" ones will have the intake either along the top or on one end wall. For home the idea is to think about the path of air flow and minimize the chances of picking up "junk" to toss into your fresh paint, along with getting rid of the fumes. If the intake is down at floor level you increase your chances of blowing crap into the paint. Keep the physics in mind too. The amount of intake air potential should be at least as big as the exhaust.

Originally Posted by buzz4041

Is there a preference for setting up your intake and exhaust ? Should they both be low to the ground or the intake higher and the exhaust low to the floor. I was thinking about my power roof ventilator that I have. Couldn't I duct that into the shop at floor level and put a filter box on it and use it as my exhaust. Then do a filter set up from under the garage door for intake as rspears post suggested. Intake on one end of booth and exhaust on the other end.

Buzz, you can absolutely duct your PRV down to near floor level, but I would not put filters on the exhaust unless you have a strong need to to protect nearby property. Filter the inlet, and let the exhaust free flow to keep the volume flow up. My paint guy is also my advisor on my paint area setup (hesitate to call it a "booth") and he suggests keeping the exhaust low, thinking that most of the dust to be picked up is on the floor. I like the idea of having the intake filters low, too. I have not yet ducted my intake down - I'm going to spray primer tomorrow and see how it works with the bank of eight furnace filters and variable speed control on the gable vent (I have about 7.5 times the surface area on intake compared to my exhaust fan area, to minimize the trash pickup potential).

Well I visited the local paint store on a fact finding mission. Very interesting, I can still buy solvent based 2 part epoxy primer, only in gallon size, and they still have solvent based paint for base coat, and clear coat. However, they can't get mail order to any town in the Bay Area Air Quality District. However a town 20 miles up the road can. He said they are trying to discourage home painters by making it too expensive.
Also have a friend with some Summit paint I may procure, so so far it sounds like water based base coat may not be the only answer, though I think I'll visit a second shop to confirm this is accurate.
Also had a good chat about Candies with him and see the error of my ways for thinking I could do this first time out. He explained how the base coat color affects the finished color, as does the number number of coats and the thickness of the coats. Also it seems that it would be much easier using a single stage paint like "Summits Paint, Single Stage, UV Stable, Acrylic Urethane"
Which was part of that do it yourself feature article in Hot rod magazine last year. Finally the price for their paint is definately right at this point. They also sell a clear coat for this paint which I'm sure will create even more questions from me when the time comes to do this.
Again thank you all for your imput and please add any tips or info towards home painting on this thread as I meant it as a starting thread for all project builders considering giving painting a try. Also with respect to the Professional painters on here, I realize you guys have a ton of knowledge in this area, and can see why you may or may not want to encourage someone to try this, considering all the places a person could screw up a paint job along the way, not to mention all the different paints and processes for each paint that seem to exist out there(it is truely overwelming).
Any tips would and are appreciated. Thanks, Steve.

I think by the first of the year 2011 , all of California has to comply to waterborne products , they can use up what solvent they have , but if they get caught spraying it , Heavy fines will incur .

Kandies are not for the average painters , they require excellent gun control & knowledge of overlaps to keep from getting tiger stripes and blotchiness & other horrific things , and the cost of having to re-do because a lack of this knowledge will kill the pocketbook !!!!

For first time sprayers its better if you stick with solid colors , either in Single Stage or Base coat clear coat . Some finer metallics in darker hues are a bit easier to spray instead of a light color high metallic .

Yes some harbor freight guns are made for beginners , but BETTER EQUIPMENT make it much easier to get a better quality job .

Get a good quality respirator that fits before attempting to spray as the chemicals you ingest can cause great bodily harm !!!!!!!!!!!

One more thing that should always be mentioned in garage painting threads is to be mindful of fire. Seems like there are often water heaters or furnaces or other devices that have pilot lights that are staged in garages. Open flame source and solvent in the air are a bad combination.

A very good point!

O.K. since we've been chatting on other threads about Fisheye, etc...Before I start epoxy primer thru my new paint gun, should I clean that gun first? If so how and with what?

Originally Posted by stovens

O.K. since we've been chatting on other threads about Fisheye, etc...Before I start epoxy primer thru my new paint gun, should I clean that gun first? If so how and with what?

Pull it apart, clean all with Lac thinner.
Then reassemble and run a cup full of lac thinner thru it, and yer good to go.