Setting up my shop

I'm a future builder who is literally starting at "square one." I'm in the process of finishing my 2-car garage and need to install some electrical wiring as the single 110 outlet that's present isn't going to cut it. Since my electrical background is minimal, I need advice. I've been told that if I have two 20amp circuits with numerous outlets it should be more than sufficient, but I'm curious if it'll hold up to an "average" RV builder's workshop workload (i.e. a window-mounted AC unit, air compressor, drill press, etc. all simultaneously being used). What additional things should I consider? Would a 220 line be helpful to have? I'm going to install additional ceiling lights as well to help brighten things up a bit. Any thoughts or comments would be greatly appreciated!

Hi Jay,

Welcome to VAF, and the greatest hobby on earth! I contemplated the very same decisions you're now looking at before I started my project. I ended up adding a number of outlets around the shop, and they have come in very handy. There's always one within reach. Most all of them are on one 20 amp circuit, but I'm not running AC. You may want to consider the power draw of the AC unit you're going to use. 99% of the time, I'm only using one power-consuming item at a time, so that's a consideration. I also added extra lighting (flourescent fixtures, low power draw).

I think by far one of the smartest things I did was to insulate and sheetrock the walls. My shop stays cooler in summer and warmer in winter. I have a 220 volt outlet, but I've never used it. The only thing I can think of that would use it would be a big compressor. Mine uses 120 volts.

Here's a shot of my shop during the work I did, before insulation and sheetrock. I'm also including below, a link to my shop page with more discussion and pictures. The biggest piece of advice I can give you is to get your kit and get going, and not worry too much about this shop stuff. One can easily get carried away trying to make the "perfect RV workshop".



Link to more:

My workshop

I second the recommendation about insulation and sheetrock - I did the same and was very happy with it before moving to the airport.

I installed two 20 amp circuits across ten outlets around the perimeter of the space. Looking back, I could have easily gotten by with fewer outlets. The air compressor, a bench top mill, and grinder were plugged in all the time but rarely running concurrently. A dremel tool, heat gun, work light, and other small items were occasionally plugged in.

Jay

You can't go wrong with more lighting than less. Try installing outlets every six feet or so and one every two feet along your bench. If you're building a detatched garage, I would consider running heavy cable over to run 220VAC in to a service panel where you could split off separate breakers for A/C, lights, outlets, (heaters?) If you have two 20 amp circuits (110VAC), you will be able to run your A/C...that's one. Your compressor, and likely an electric drill or drill press, some lights, but likely not at compressor start up. It depends on your wiring lengths and wire gauge. Prime and paint your drywall sheathing white. Good luck.
Oh ya, I installed in the center of the ceiling, one of those retractable electric extension cords with a triple outlet end......I use it EVERY day. I also installed the air version. Same thing, very handy.

My building room is 16 X 32, insulated and sheetrocked, with a walk thru door on the side and a garage door in the end and is inside my hangar.

I ran a 60amp service to a sub panel in my room off my hangar panel. Off that I ran 3 20amp circuits, 2 for lights and receps and the 3rd for a dedicated circuit for the window unit a/c. I put up 3 8' high output 2 bulb flourscent lights. I also put 2 receps in the ceiling. Oh, I used 2 gang boxes with 2 duplex receps (4 outlets) on the walls.

I piped air in from the 60 gallon 220volt compressor that's mounted on the floor on the opposite side of the hangar. I used 3/4" black steel pipe for this. Don't use PVC for air, it's just dangerous.

I'm a licensed plumber and electrician, have all the tools and threaders so I thought this was easiest/smartest way to go.

BTW, I think Paul Dye has been in my shop.

Marshall Alexander

Easy to get carried away

I have to agree with Bruce, I?ve been getting a little ?carried away? with setting up my shop since we?ve moved to a 3 car garage (with a house attached). We got a gas dryer so I could snag the 220 circuit for my compressor and drill press. I?ve since added a 50 amp 220 circuit (for a future welder) as well as an extra 20 amp 110 circuit. I?m enough of an electrician to know I?m NOT an electrician! But I get by. I?ve put in over 110 feet of ? inch black iron pipe to plum air to every conceivable place I might want it, along with an overhead hose reel. I?ve got 4- 6 light florescent light fixtures, and want to add at least one more. When you get to a certain age, you can?t have too much light! I?m starting to run out of excuses, and need to get back to work on the plane! Like I said, pay attention to what Bruce said in the 1st response, I?m a prime example.

If your main panel is not in the garage definitely go with the 220 sub-panel suggestion, that way you can add on whatever you want in the future, and if you were to blow a breaker you can walk over and reset it.

One garage that I retrofitted had studs on 24" spacing and I was not sure if 48" outlets were enough. I put boxes every 24" and outlets in ever other one with a loop of romex and a cover plate on the vacant ones. I never used the covered boxes.

If your walls are open consider plumbing air at the same time. We now sell the rapidair kit that makes it pretty slick.
http://www.cleavelandtoolstore.com/prodinfo.asp?number=ACRAKIT

And as mentioned in other posts, consider building a 'dog house' outside for your compressor, or at least run the air intake filter outside to reduce noise.

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BSwayze said:

One can easily get carried away trying to make the "perfect RV workshop".

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Hey Bruce...I resemble that remark!

Welcome Jay!

I built a shop in my back yard and added a 60A subpanel strictly for the shop this last winter. The process is still fresh on my mind.

I have 3 20A outlet circuits with about 5 outlets each on them. I also added 4 lighting circuits for various areas mostly for convenience of wiring them rather than splicing off power from 1 or 2 breakers to multiple switches. I had the breakers laying around and the panel space.

Lastly, I have a 20A 240V for the compressor. I have no desire to learn the art of welding and I did not want to have to run the larger conductors from the house for more Amps for the service to support a larger 240V circuit anyway. The next owner can worry about that.

Needless to say...I am pleased as punch and can run all that I will need to build my RV with capacity to spare. You can check out my insanity in the RV Factory gallery to see.

Either way, it is not hard to do...just be careful and don't skimp to save a buck or two. Protect the supply conductors well so you do not run the risk of hitting them with a nail or screw down the road.

Where is the main supply panel in reference to your garage? That will help in the decision making process as well.

Get ready for some real fun!

Cheap to add circuits now with the wall open, so I'd add at least 1 220V 20A outlet and a minimum of 2 (better yet 4) 120V 20A circuits.

I insulated and then used 3/4" plywood instead of sheetrock. Makes it easy to screw things to the wall.

There are a few things which you simply cannot ever have too much of in a shop. Lights and electrical circuits are definitely both on the list. Two 20 amp circuits for outlets should be plenty. For outlets. But as long as you're doing electrical, run a separate independent circuit for your AC. Since you already know AC will be installed, you might as well put it on its own breaker.

And consider adding a 220 outlet for a compressor. Yes you can do it with a 110 compressor but once you use a 220 compressor you'll never want to go back. Allowing for that now will be much easier than trying to do it later.

Hi Jay! Welcome aboard

Lot's of good advice has been given already. I did the same as you... built my shop specifically for aircraft construction. You can see all the details here. If you use the category links you can find LOTS of posts of me building the shop, insulating, running electrical, compressed air piping, etc.

The short of it is this; you cant have too much power or too much light. 1W per sq. ft. is recommended. Also, use copper not black iron pipe. See this link about copper piping in particular. It includes references to orifice flow calculations and general compressed air piping information.

To everyone else thats posted here, I'd like to humbly point out that when speaking of one-phase three-wire 60Hz power in the United States the standard is either 120V or 240V. 110V/220V hasn't been in use since the early 1900's Poly-phase power is something else entirely, of course.

Happy building!

jlott said:

Hi Jay! Welcome aboard


To everyone else thats posted here, I'd like to humbly point out that when speaking of one-phase three-wire 60Hz power in the United States the standard is either 120V or 240V. 110V/220V hasn't been in use since the early 1900's Poly-phase power is something else entirely, of course.

Happy building!

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Of course you are correct.

Up here in Canada, we have this 6% torerance thing going on.
(Some times it gets so cold, the water freezes to the power plants and it affects the voltage)
The metered voltage indication from my shop outlets are 113VAC, but 120VAC is the standard.
Regards

lorne green said:

The metered voltage indication from my shop outlets are 113VAC, but 120VAC is the standard.

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Cutting it awfully close aren't they?

clevtool said:

And as mentioned in other posts, consider building a 'dog house' outside for your compressor, or at least run the air intake filter outside to reduce noise.

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Granger has an intake muffler for compressors that work very well. My comp is a 23 cfm it is in a inside room that is connected to my garage and is not a problem.................... the neighbors can't hear it.

Talking about mufflers: http://www.vansairforce.com/community/showthread.php?t=54705

I copied this idea and it works very well for me. Two weeks ago the hose from the muffler to the compressor slipped out and the compressor suddenly was so loud that I thought it broke.

Fluorescent lighting gouge

For what its worth, when I set up my last shop, I ran across some useful information on how to gauge the amount of fluorescent light a shop should have. The number I used was .75 watts per square foot, which worked out great.

I just checked my shop and I have 1.0 watts of fluorescent light per square foot. It's adequate, no more than that, but then again I'm over 60.

Additional task lighting would be a reasonable thing to have on a separate switch.

Dave

Interesting conversation on lighting. I am at 1.75w/sqft according to my calculations. People driving by ask what I am growing if the shop door is open.

The color of the walls will make a difference to due to reflectivity. As stated here I am at 1.33W/sq.ft. and I find it to be just about right for detail work. My walls are all painted white.

The lighting is on two circuits as well so I can turn half the ballasts off if I choose. I rarely do though.

Compressor Choice

Jay,

I would say that the comments from everyone are spot on. The three most important things you need (with regard to electrical only) are lights, receptacles and compressor capacity. That being said, I struggled with the decision about running a 220V circuit into my garage for the longest time. After using some online calculators to determine whether my panel could handle an additional 220 circuit, I realized that it couldn't. I didn't want to pay an electrician to install another panel on my house, so I set about looking for the largest capacity compressor I could find (economically) that would 1) fill fast, 2) have enough capacity, and 3) run on 110V. What i settled on was a 30 gallon oiled compressor from Harbor Freight. It's got 2HP, 150 psi max, it's quiter than the oil-less ones, and the 30 gallons seems to be adequate for RV Building. For the longest time, I yearned for a 60 gallon oiled. However, I won't be using it to paint, and the only time it ever cuts on very much is when I'm using a die grinder for a long time. It was cheaper than the large ones, and I could use the available power to run other things, like lights, receptacles, fridge, etc. Good luck with your shop. Be sure to make it nice because you'll be spending a lot of time in there, however, don't get bogged down trying to build it to Piper Factory specs.