Technical The Painting at home in the driveway or garage thread

You can get some really big mosquito nets for $20, so I can absolutely see the screen concept. As long as a stray gust can't blow it into the paint. That netting I bought just flies in the lightest wind.

 

I myself don't recommend painting in a garage. Had a friend blow his up doing that. If you must make sure you have good quality fans pulling the overspray out. Years ago I would bend copper line and drill pin holes to put around the fans. Solder on a hose bib and connect a garden hose. If painting in a neighborhood this keeps the overspray down. Also make sure your compresser is not in the same room your painting in.


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My best bug advice, start EARLY in the AM, like at the ass crack of dawn. Bugs are going to bed then, neighbors arent quite woke up yet. win win

 

Painting in a garage is one of the primary topics of my thread.
Done properly it is more than safe.
Blowing up a garage is simply a case of not thinking and doing what is required to be safe.
1) I have a heater that is a radiant tube heater, the burner box is fully isolated from the shop environment taking in combustion air from the outside, no standing pilot and not effected by any shop fumes.
2) Using a Turbine HVLP system takes the problem of the compressor out of the equation, and also ensures a very low level of overspray, in some cases less than what comes off a rattle can.
The turbine can be placed in a location outside the garage so its isolated as well.
Again, as lots of guys posting here have proven it can be done, done well and safely too.

 

Well I do have a gas water heater and an automatic air compressor both in the garage, and they will both be an issue if I ever get to paint in there again.

I can shut off the gas, and tow the compressor outside, plus I'll have a filtered exhaust fan, and together that should prevent any random explosions.

 

I've never used one, but they do sound very practical, and more efficient than my old suction-type Binks clone.

 

All I own are siphon feed paint guns, I've never sprayed with a HVLP gun before, but with the high price of paint anymore, I may be switching over.

 

Slow reducer may help you keep a wet edge as you work, the flipside is it stays wet longer for bugs and dust to fall in.

 

I understand that it can be done relativly safely, and I have done it myself many times. The thing to remember is it only takes 1 spark to ruin your day. That can come from noexplosion proof fans and lights,not to mention air compressors. Most new painters don't have the turbine system you speak of and are still using siphon style guns which does create a lot of overspray when not removed can explode. I have seen this first hand, from a painter that had painted like this for years. A single box fan is not enough to pull that amount of overspray out safely , if you must use 4 box fans and put some type of filter over the motors to reduce the amount of fumes in the area were sparks are present. Also set the fans so your pulling from top and bottom because the fumes will rise into the rafters or attic. Do not paint with a closed garage door, use plastic to cover the opening, this will help not only with a blow out but also if for some reason you can't breath it provides an easy out.With a little leg work you can find a body shop that wil rent out a booth for 100-200 $. If you do alot of painting this is a better option. I have strong feelings on this subject due to the fact I lost a good friend ,and a family lost there father.
.

 

Sorry that you lost a friend, it's time to get back to the purpose of the thread, lets see some more prep and painting

 

Quick tip; if you leave your overhead door open or partly open, cover the outside of the door with plastic as the overspray will settle on the horizontal portion. Guys at work ended up leaving a 4' band of black overspray on a white fiberglass door.

 

I have a build going on right now that goes with this thread. Click below to see. 100% done in one side of the garage. If anyone has questions feel free to ask. I use a couple of buckets of water 20-30 min. to wet the floor before painting. The best way to have are flow is to create an exhaust fan by simply running fans in front of the garage opening pulling away the fumes, this will allow for a dust free paint job. http://www.jalopyjournal.com/forum/threads/1937-ford-truck-hot-rod-roadster-build”.925593/
Todd

 

I have a garage that is more of a showroom than a work space. I just bought a 10 x 20 x8 portable garage to put in the driveway. I need to add another coat of high build primer on my 40 pickup and I bought the portable garage to handle this.
I understand the need to ventilate it with a fan but my concern is the paint flowing out of the fan will end up on my daily drivers and our recently remodeled house. Any suggestions on how to limit the paint blown out of the fan?

 

You can use furnace filters to capture the bulk of the paint. They are readily available and cheap, just tape a few together and make a filtered air intake as well as exhaust.

 

All good tips which I will be using. I'm hoping to get good results with my attempt at painting.

 

What Blue said, let's see more cars/parts painted

 

I painted mine in the garage, two stage metallic. It came out good. Had to color sand it to smooth it out ( first car I've painted in 15 years lol ). The wife was really pissed about the floor though. I had to rent a floor sander to clean it, and it took all day to do. I will never paint another car in the garage after that! I think it's best to rent a booth if at all possible. Usually they supply the air compressor which is nice too.

 

Beautiful coupe 1951hudson

 

I'll not trust furnace filters to protect much of anything of value. Years ago, my cousin was painting in his sister's attached garage...the furnace sucked in the airborne paint and distributed it all through the house. A few years back we were taking down the ceiling in a 100+ year old house that had been heated by fireplaces for a lot of years. Because of chimneys that had leaked back in the day there was a large amount of soot trapped between the ceiling and the floor above. Taking down the ceiling stirred up the soot, and the furnace distributed it all through the house. In both cases, furnace filters failed to stop major ruination.

 

Filters used in paint booths are similar to furnace filters, just thicker, so if you use more than 1 layer of filters they will trap most of the airborne paint. Also they make more than one quality of furnace filters, the better quality will trap more than the lesser will. Most furnace duct systems are not built to hold the filters tight enough that I would paint in an area that has a return air duct in it for one reason being that the filters will not remove the solvents and would leave you in an explosive situation.

 

All good points. I guess it boils down to 1 run of the mill furnace filter, set up in typical furnace fashion, is not going to cut it.

As an alternative, I'd be tempted to try to build a large scale version of the water filtration used to trap drywall dust when sanding

 

Thanks Apache!

 

You know that you can buy cheap painting drop cloths to cover the floor. No muss and easier than trying to clean the floor afterwards.
It's called planning and working smart.

 

Yeah, Hind sight is always 20/20

 

I LOVE IT!!!!

 

Beautiful job!!! Hay!!! Can I get ya to paint my car shiny???? BWWAAAHAAAHAA just had to say it...

 

A few basics for people who are planning to construct some sort of booth with air moving capability.....

Its better to operate the booth under positive pressure than negative. IOW, blow air into the booth instead of sucking it out. This prevents dirt and dust from being sucked in anywhere the booth isn't sealed off.

Simple box fans are near useless for moving air if you plan to filter it. They will move large amounts of air under no resistance, but once you add the pressure drop across filters, their air capacity drops to near zero.

A used electric furnace or heat pump/air conditioner indoor unit makes a decent supply air unit. Most hvac contractors have them regularly from unit changeouts and are happy to get a few bucks from them instead of throwing them out with the trash. All you need is the fan and the housing. Any cooling coil or electric heat should be removed along with any internal insulation. The fan wheel in used units is normally dirty, so a good cleaning with purple stuff or similar is high on the list of things to do. These units will typically move 1500 to 2000 cfm at 1/2" static pressure which is enough to overcome the resistance of inlet and outlet filters. Because the unit is set up to blow air into the booth, there's no worry about it needing to be able to handle potentially explosive atmospheres. With a booth sized at 15 x 25 x 8ft high, this would give you an air change about every 1.5 to 2 minutes. Not up to the air change quantities of commercial booths, but plenty good enough for a DIY setup.

The exhaust outlet of the booth would use paint arrestor pads. These are special filters made to trap paint. Less than $40 for a box of 50 at http://boothfilterstore.com/22-gram-fiberglass-spray-arrestor-pads.html The velocity thru paint arrestors has to be fairly slow for them to work properly. About 150 ft/minute is a good average value. To determine how much filter area you need, you take the total air volume and divide by the desired velocity and get the answer in square feet of filter area. For example, with 1500 cfm supply, you'd have 1500/150 = 10 sq ft. The requirement of low velocity across the paint arrestors is why you often see a wall of filters across one end of a commercial booth. They typically handle a lot more air than a home built one would, but the velocity requirements stay the same so the filter area gets larger

On the air supply side, the safest place to put filters is at the entrance to the booth. If you put them at the entering side of the fan unit, you run the chance of blowing out any dirt that's anywhere between the fan and the booth. The pleated high efficiency filters available at hardware and home stores will work. 7-8 bucks apiece. The discharge velocity from these filters should be low as well. Both to aid their filtering efficiency and to keep from stirring up anything that may be in the booth. Ideally, 4 or 5 outlets to fit 20x20 filters would keep the velocity in the desired range.

Its not practical to try to create a downflow booth. I'd put the inlet at one end and the outlet at the opposite end. Best to keep the air inlets in the ceiling if possible, spread evenly across the width and at least a foot away from nearby walls. Don't have them positioned where they're blowing on the car. Put the exhaust filters (paint arrestors) low on the opposite end wall.

None of this really matters if the booth isn't spotlessly clean before you paint. A vacuum works, but a blow gun just rearranges the dirt and dust so it can fall on the paint at the worst time.

And finally, don't run the fan any longer than necessary. In general, it should be turned off once the last coat flashes off. Running the fan too long doesn't make it dry any faster, but it does increase the chance of junk landing in the paint while its still tacky.

 

A lot of these issues are exactly why I chose to paint my truck in lacquer when the time comes (soon I hope). I wanted the look of lacquer over the plasticy look of new paints but it is also easier to spray in a home environment, not as deadly (still not safe but not as bad as urethanes) and fewer concerns with crap getting in the paint before it dries. I have painted a few small things with both urethanes and lacquers in my garage and everything I spray with urethane somehow ends up with something in it no matter how hard I try to keep things clean and I have never had even a speck of dust in anything I have painted in lacquer.

I know all the arguments against lacquer that it won't last as long and is not as durable but realistically it is not going to be exposed to that much inclement weather here as it will be in the garage for 6-8 months of the year, we don't get the blazing sun like places in the southern U.S. and it's not going to be a daily driver so I am pretty confident it will last a good amount of time.

 

I had a friend that used a swamp cooler running backwards to filter his paint fumes. Worked real good.

 

Just painted my 32 bantam coupe this week using global acrylic enamel in calif. Must say their product works well and lays down nicely. I bought one of those harbor freight portable garages and used it for a paint booth with household cold air return filters at both ends and a fan drawing at one end though the filter. With a wet floor, the foreign matter was kept to a minimum. It is obvious that it is not a pro job but I`m happy with it. Here in ca. it is 100 degrees during the day so I had to spray before 6 am.