I'm sorry if this is a silly question/topic. I'm still in the researching stage for my restoration. I was at the local autobody supply store yesterday and was asking them about spraying epoxy primer with a gun vs. using etching primer in a rattle can. I don't have a gun and have never used one. I know Jeff Hail's thread says to spray epoxy primer after each area is repaired. They said that either way (i.e., even with a rattle can) there is an issue with overspray. I don't have a dedicated shop and there is literally no place at my house where I would want overspray. They told me a story about overspray going hundreds of feet. So, I was thinking that what I could do is have a tarp on the concrete under the car (plan is to make a bench a la Hail) and drape a poly tarp over the car. I can't tape poly to the ceiling to make a pseudo paint booth because the garage door would hit it when it's open. I suppose I could make a makeshift poly tent that fits under the garage door. But, I would think that lack of ventilation would be a big problem. Would this work? Be too unsafe? Better to rent a workspace and do all the metal work/priming elsewhere? Your thoughts and experiences would be helpful.

For what you are doing, see if you can get epoxy in a spray can.

Just tape up what you do not want to get hit on the car. If there is stuff that can not have any overspray on it in your garage toss a tarp over it. If you were painting the entire car I'd be more concerned, but you are not going to get a lot of over spray from doing patches.

Zach

I asked them if they'd heard of the 2K in a can, and they hadn't. From what I've read, probably on this forum, the 2K in a can is generally not considered worth using.

Would the idea of a poly tent work, or would that be too problematic for ventilation?

If you watch Dexter (great show) keep him in mind when you create a paint booth out of plastic in your garage. Better to be safe than sorry.

Don't worry so mu h about overspray. Tape off areas near to where your spraying and go for it. The little overspray on the farther areas will be paint that is nearly dry and you can clean it off later

When I paint in the garage, pretty much everything gets coated with a layer of dried paint dust.

The only place I've had an issue with overspray is the window screen where I used a box fan to evacuate the garage. Only did that once. Now I remove the screen before painting.

Overspray usually happens with crappy nozzles that spray the paint everywhere. Some of the paint goes onto the intended areas and some of the paint semi- dries in the air as dry or tacky balls that drift around onto the just sprayed paint, onto parts of the car you didn't want to paint, and some onto the floor. Corners increase the risk of overspray as the propellant bounces off the surfaces. Think spraying into the wind.

Rattlecans are notorious for crappy nozzles and overspray. Sometimes the paint layer is nothing more than a bunch of semi-tacky paint balls sticking together with gaps between. Not real fond of rattlecans and use them sometimes, but know what to expect.

One thing I did to avoid overspray was to buy a HVLP system with about 96% paint transmission. Paint goes on like fogging a mirror with your breath, and only 4% drifts around into unintended areas.

Hmmm.... I've seen a few episodes of Dexter but don't recall his 'overspray prevention booth'.

Sounds like it will be dry before it lands on things that are more than a few feet away.

I've heard that for spraying primer just a cheap ($40) gun is fine. However, should I get the kind mentioned above even for primer to reduce the amount of overspray? Or, is epoxy primer a different animal?

Thanks, guys, for you helpful advice.

the principle is the same though.....

With epoxy just use a small HVLP touch-up gun and lower the pressure a bit, you wont get that much overspray doing small areas. Doing a whole side of car with a full size gun at normal tip pressure for 2k primer, base or clear and it will be floating around and settling on things you don't want. HVLP is more efficient than the old conventional guns but there will still be overspray and you still have to cover things that you don't want messed up.

Just to clarify, are you saying that with a small HVLP touch up gun and just doing my patches as I go. overspray onto other things in my garage is unlikely to be an issue? Just not sure if your last sentence is referring to both the small and larger gun options, or just the latter.

Is there a particular brand/model of gun to get in terms of doing the correct job and ease of cleaning?

I think you just need to use some good judgment, and cover up things of value even if just from a spray can. If you have another car in the garage, move it out or cover it with plastic. With a small gun that has the pressure dialed down a bit, and just covering some welds or small areas, you won't have a fog of spray all over the place like you can get when painting a complete car. Cover adjacent areas with plastic or tarps, cover anything you don't want any dust or uncatalysed primers settling on. Maybe I'm not explaining this well, but spraying a couple of welds or bare metal areas will keep the overspray concern close to where you are working. But if you are spraying complete panels at high pressures you will trash everything in the garage if it's not covered up, and you don't have some kind of controlled ventilation.

Okay, makes sense, thanks! Any recommended brand/model of small touch-up gun (for minimizing overspray and for ease of cleanliness)?

For small primer jobs I get the cheap HVLP guns from Harbor Freight, using the coupons. They have a 5 oz touch up gun that will work fine for epoxy or 2k primer for small patch areas. Run some lacquer thinner through it before using it to clean it out and check that's it's working properly. Get a gauge for it and you can lower the pressure a few psi from the typical 23 to keep overspray to a minimum. You'll get more orange peel but if it's just to cover up repairs for later sanding and final bodywork, you can block that out later. I'm assuming you just want to get epoxy over some areas to prevent surface rust. Make sure you use a proper degreaser before spraying the primer.

Yeah, I'm only looking to cover the area's I'll have patched, though there may be many of those .

I'd like to contain overspray and dust from removing the paint and grinding the welds. I did some internet searching. Seems that a tent can be made from pvc piping and poly. I'm thinking maybe I could make one big enough to cover the whole car and use that to keep the dust and overspray in.

Definitely been done before and though it won't be perfect, it's usually a good option for the rest of us doing things on a budget.

Remember though, you need more room to paint than you'll ever think. Its not as simple as building a box around the car, you need to leave yourself room to move within it, otherwise you'll be rubbing up against fresh paint. If you go that route, be sure to have a QUALITY respirator.

Yea, I'd have to make it big enough to be able to open the doors. I was thinking that, since I will only do small patches at a time, ventilation may not be a big problem. But, with no air movement it would get stuffy in there. Maybe I could rig it so the poly rolls up on all 4 sides during fitting and welding, then lower the poly for grinding and patch priming. It wouldn't be completely sealed this way, but, if the poly pieces overlap, would probably be sufficient to keep overspray and most of the dust in.

You are over thinking this IMO.
In a garage you don't have wind blowing paint all over.
An HVLP gun makes little overspray.
Just use common sense and go for it. You are going to spend more time mixing the pain then painting.

There are epoxy primers in rattle cans. You twist something to release the hardener. Then you shake and spray. It will produce a completely different type of covering than a single stage paint and it will stick. Eastwood and autobody supply both sell them. If it is small you can make a plastic booth to cover everything you are doing. Different paints create different amounts of overspray with the finish coats drifting farthest.

I didn't know they had epoxy primers with hardener in the can! That's cool. The other way you could go about doing this might be to try the Preval sprayer one can buy at Home Depot. Works very well with paint, but primer might be too thick.. I'm not sure. Its a cheap experiment though. The only problem with them is that you are really limited to how much you can tilt the bottle/sprayer - it only works up to 45 degrees off level.

I agree with Zach too, you're overthinking this. If you do have any overspray, you can use a clay bar to get rid of it as well. I can't stress enough though the use of a respirator!

Thanks for all of the advice guys. I will use a 3m half mask respirator for vapor and a dust prefilter. Don't have the air supply type.

I'm sure I'm worrying too much. I was a bit freaked out by the autobody shop guy telling me about overspray traveling so far. Also, I tried to learn how to weld sheet metal on practice pieces in my garage over the winter and just the other day realized how much dust from grinding was in places that I didn't expect it. So, this also contributed to my concern about messing up things that I don't want damaged.

The 2K epoxy in a can does not get good reviews on the net. I also imagine, just guessing, that one would have to use up the can in one sitting. Wouldn't be practical for doing a patch per weekend. But a neat concept nevertheless.