Spray Shop Layout

Setting up an efficient spray-finishing area in an expanded shop. December 26, 2004

Currently, we manufacture kitchen and other cabinets, including shop fitting. We will soon be moving to a larger workshop. Next year, we will expand to manufacture kitchen doors for other companies.

We will be doing our own painting on the doors. At present, we have just a small booth for our own occasional jobs. In the new workshop, we need to build a fully functioning spray shop. Can you provide some tips on spray shop layout to help us with our planning?

Our new workshop will have an area set apart from the cabinet shop and CNC area. We will probably create a partition wall if we need to do so. So assume the spray shop area will be in a room of its own with a large roll-down door on one end. For now, disregard dimensions, as I have none, but by all means suggest the best working areas required.

The main things I am looking to gain is a better idea of the floor plan layout - what work areas need to be in what places. Example: right now, we find any place we can to mix up paint, and mostly it's done on the floor someplace. I assume you guys have a paint mixing area and some specific items you use for this task.

Our planned maximum production will be in the region of 120 to 150 cab doors a day, one sprayer doing the lot.

One other question: We have been advised to go for a HVLP setup (FUJI System) at $2900 Australian rather than to continue with our normal spray guns. We have been told the finish will be better. Your opinion on this would be welcome.

I like my traditional way of spraying. After spraying cars, then stove enamel, and now cabinets and doors for years, I am a little worried about moving to a new method. But if for sure the HLVP method will provide significant improvements in finish or ease, then I should probably get into it. (We spray two pack mostly.)

Forum Responses
(Finishing Forum)
From contributor M:
I had the Fuji system and it did a good job. Then I bought the Kremlin and it sprays like a dream.

From contributor B:
For production work like that, there's no comparison with air assist airless like the Kremlin. My first choice. Little more expensive, but will pay for itself with time saved in loading and transfer efficiency.

From contributor C:
One sprayer to do 120 to 150 cabinet doors a day? I hope you give him a couple of helpers for sanding sealer coats, as well as a hand staining.

On my own, shooting precat with an airless gun on natural oak paneled doors, start to finish, I can only get 50 to 75 doors done a day. That includes seal coat front and back, sanding and filling imperfections, nail holes, blow outs. And then topcoating the inside, followed by two topcoats on the outside. Staining obviously decreases the output, even if someone else is staining for the finisher. Glue marks, stain drips and other defects get rejected, hopefully before being sprayed. Sometimes, though, things just don't show up until the lacquer hits them.

At that production rate, your finisher needs two assistants to keep up with him. Much more than two and he will have a hard time keeping them supplied with doors to sand.

Take that into account with the size of your shop layout. The sanders will need an area outside of the spray area to do their sanding or will have to wear respirators all day long, as well.

I'd recommend rolling racks for the doors similar to a Hafele rack. They hold 50 doors each and can be wheeled out to the sanders and then back in for topcoating. I'd go with movable benches and work areas, so the sprayer can alter things inside to adjust for changes without a major hassle.

Throw away the sawhorses and make some simple spray stands. I have three 5 gallon cans filled with concrete with a metal pipe sunk into them. On top of the posts I set stands up for my smallest drawer front and another set for the smallest door. Mount a floor flange to each board and screw in a pipe nipple that will slide in and out of the pipe you set into the concrete. No moving sawhorses around to adjust for different sized pieces. The top of the stand can rotate to avoid over reaching. If they do need to be moved, they roll very easily while holding the top to steer it. They also clean up a lot easier and quicker than sawhorses.

From the original questioner:
Thank you. For now we will continue to use the existing setup unless either the HVLP or air assisted can prove the finish is better or it aids production, i.e. reduce cleaning, provide improved and easy colour change, etc. I have noted time and time again the good words placed on the Kremlin setup, so your points are taken.

I honestly thought I would be able to work up to 150 doors a day on my own with the CNC man doing the initial sanding. But it sounds like this is not feasible, and as such, we need to take into account additional wages and cost for at least two helpers or one helper and one additional sprayer who can step up to the plate on off days, etc.

Contributor C, can you describe the stands to me in more detail?

From contributor C:
Here is what you need for one stand: an empty 5 gallon can, 60 lb bag of concrete mix, 30" length of 1" inside diameter copper pipe, 3/4" cast iron nipple 4" long and a 3/4" cast iron floor flange.

Take a board just smaller than your smallest door size and screw the flange to it, then thread the nipple into the flange. You now have the part of the stand done that the doors will rest on. Repeat this for as many stands as you want to build or as many different sized sets as you want.

I have two sets of three stand tops, one set for drawer fronts, the other for doors since the larger doors can be unstable on a piece of wood small enough for a drawer front. When I switch from drawers to doors, I just lift one top out and drop the other in.

Next, you want to cut a hole in the can lid so the copper pipe can slide through. Fill the can with concrete mix and set the pipe in. You can set the pipe in the concrete at a very slight pitch or perfectly plumb. Once the concrete has cured, slide the lid down the pipe and secure it back to the can to keep overspray from collecting on top of the concrete. You now have a very heavy 5 gallon can with a pipe sticking out of it and it's only a matter of hitting it with a broom or brush to clean it.

Now take the wood, flange and nipple assembly and insert the nipple into the copper pipe. You may need to bang it with a mallet to get the nipple into the pipe if the pipe's end was crimped a bit in the cutting. After that, it should rotate with a little bit of effort but not be able to spin freely. Almost like a Lazy Suzan setup.

Depending on what is a comfortable height for you to spray at, you will need to cut some of the top off the pipe. 29" is the level that works for me.

I use the foam sanding blocks for my seal coats. When those aren't cutting it for sanding anymore, I put them on the stands to keep the doors from being scratched up. There's not enough grit left to trash a finish, but just enough to keep the doors from sliding around on top of the stands. Shoot a couple of brads into the area where the sponge block would sit and then impale the blocks onto them. This will keep the blocks from falling off when you move the doors.

These stands are sturdy and don't loosen up and wobble over time like sawhorses do, and they are a lot easier to clean off.

As for work benches, I'd put them on wheels so they can be moved around in the shop. Get the wheels that can be locked so they don't roll when you don't want them to. One for sanding, one for staining, and one for cleaning and mixing. Cabinets and drawers can be built into the rolling benches so the supplies being used are in the bench - sandpaper of various grits, sanding blocks/sponges, tack rags, brushes and clean rags, gloves, etc.

Don't forget some good lighting that comes across the piece, rather than straight down on it like overhead lighting. If you're shooting solvent based, it will have to be explosion proof lighting.

Depending on the size of the finishing room, you'll also need a separate area to take the items once they've flashed off so they can finish curing enough to be assembled.

From contributor J:
The only way you are going to be able to do 120-150 doors a day is if you do both sides at the same time. And the only way to do that is to hang them. I use a moving chain that takes the doors through four stations. Stain, sealer sand and lacquer with pre-cat lacquer. The chain takes an hour to go around once. Then at the end, I take them off and put them on a rack where they sit for another three hours until they are ready to either pack or mount on the cabinets. I use only spray-on stains, a catalyzed vinyl sealer, and two coats of pre-cat lacquer. I use a Graco Mercur 20:1 air-assisted airless with a Binks AA-1500 air-assisted airless for sealer and pre-cat lacquer. Works good for spraying 150 kitchens a week.

From contributor B:
Contributor J, what spray only stains do you use if you don't mind sharing that info?

From contributor T:
And how long you need to dry them before sealer?

From contributor R:
Contributor J, I like the idea of spraying both sides at once to save time. I don't hang them, however, I spray one side and flip it right over to spray the other side. When spraying them while hanging, how do you sand the sealer coats or primer coats if you're doing a pigmented finish?

From contributor J:
I use Sherwin-Willaims dye stain concentrates to bring the color to 80% of the color needed. Then I use a 400% thinned vinyl sealer with SW wiping stain concentrates to even the stain as a toner. Then I spray SW fast dry vinyl sealer catalyzed and it's ready to sand in about four minutes. Then two coats of SW pre-cat lacquer

Contribuor R, I have two people with Scotch-Brite pads sanding them as they move by on the chain line. You just need to knock off the big chunks of roughness as they go by, then let the lacquer do its work to fill in. That's why I use air-assisted airless, so I can apply the lacquer full strength. A conventional sprayer won't keep up with the lacquer at that viscosity. Especially HVLP. When I need to make deadlines, I use a piece of 1/4 melamine with screws through it. Put it on the flatline, spray one side, then turn it over on the screws and spray the other side right away. It only leaves small, almost undetectable, marks on the back of the door and I've skipped a step to speed things up.