Contributor
In my opinion, it would be far better to omit the water/DNA wipe and sanding, and spray a 1 - 2# cut of dewaxed, classic alcohol based shellac as a sealer over the "cured" BLO. This is a time tested recipe for sealing BLO and providing adhesion of subsequent topcoats. With no disrespect to Target, I think that recommendation has more to do with selling their products than anything else.Originally Posted by Mike King
John
Moderator
I spray shellac and Target EM6000 mostly and some dyes (and occasional latex) with my Apollo 1000 HVLP 4-stage turbine sprayer. I use the large cardboard box from our refrigerator cut and clamped together appropriately and propped on top of my workbench (MFT1080). I spray in my garage after a good blowing out (often need to blow out a couple times) and the cardboard folds up nicely to store behind the bench.
Contributor
I've used cardboard, and stapled some 1X3 to make a frame to mount a cheap box fan. I forget how I held in the fan, but it was nothing fancy. I may have just used C Clamps, actually.
Member
>>>> i have no experience with spraying finishes
Then again, I strongly suggest you learn how to spray by testing on scrap wood or cardboard. A book titled Spray Finishing by Charron is also an excellent investment. Items like desks can be difficult to spray properly. Finish blows back when you try to spray interior areas. You need to think about how to spray certain surfaces or the finish can just Just loading up the gun and pulling the trigger will not give you good results.
Howie.........
Moderator
My shop is in a separate, nearly dedicated building.
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The most expensive tool is the one you buy "cheaply" and often...
Member
For what its worth, i've been told by Target (and read anecdotal reports) that not all their products do so well over shellac. That would be my normal schedule as well, but per Target's recommendation I used their brand of sealer on my last piece and it worked fine. Doesn't look quite as nice as shellac, though.in my opinion, it would be far better to omit the water/DNA wipe and sanding, and spray a 1 - 2# cut of dewaxed, classic alcohol based shellac as a sealer over the "cured" BLO. This is a time tested recipe for sealing BLO and providing adhesion of subsequent topcoats.
Melad StudioWorks
North Brookfield, MA
Member
I'm about to construct a paint booth for water bourne finishes in my basement. I think I will just hang plastic from the floor joists. The only tricky part is the fan. I have a nice window at the back of where the booth will go, but I don't want to just stick a fan in there because I will lose heat in the winter and make conditions too cold for spraying. I am thinking of using the same fan that vents a bathroom and running a hose through a fitted piece of wood in the window.
Any suggestions?
Contributor
Paul, I use my 1200 CFM dust collector fan to vent my temporary spray booth in my basement shop. I live near Niagara Falls and it gets pretty cold here most of the Winter. I can spray for at least an hour w/o the temp. changing more than 1 or 2 degrees. All the mass in my shop tempers the effect of the cold make up air. Unless your shop is tiny and has nothing in it I think you could expect something pretty similar. I used to use a smaller squirrel cage fan of around 400 CFM, but it didn't capture all the over spray like the 1200 CFM one does. I don't use any filters in front of the DC fan; they just clog up. Whatever goes into the fan is dry by the time it gets there so there's no build up on it and dry powder goes outside.
I spray WB and shellac ONLY.
John
Member
Mike I am space limited, as my shop is in one bay of my garage. I made my spray booth by screwing hooks into the ceiling around the bay I park my wife's car in. I have some cloth drop cloths that I put grommets in, to match the hooks in the ceiling, and I just move the car outside, hang the cloths from the hooks and make the booth, when I am ready to spray something. I have a big plastic tarp that I put on the floor, to catch overspray and I have a carpet dryer style blower fan that I setup to exhaust the air out the bottom of the garage door. I used the cloth instead of plastic to keep the static electricity down. This setup has worked well for me and I only spray waterborne finishes.
Earl
Member
The bathroom fan I bought only has a CFM of 60. I bought a piece of plexi glass to put in my window so I could vent the hose through it. I cracked the first piece when trying to use a knife for the hole. I went to the box store and bought a hole saw. I tested it on the cracked piece--no problem. I drilled the hole in my second piece, and it cracked too.
All this aggravation for a small fan that may not do anything. Should I give up on the small fan idea? You note that 400 CFM fan didn't even do everything you want. At work I expressed my skepticism that running a fan in a window for an hour in the winter wouldn't cool down my workshop, and my friends noted that since the fan blew out, it probably wouldn't cool things down too much (as you have already experienced!).
Contributor
IMO, a 60 CFM fan is of no value unless the open area of your booth is only the size of a shoe box. Spray booths are designed for something like 100 fpm of velocity over the work to carry away over spray. For a booth with an open area of just 2 ft x 2 ft you need a fan with 400 cfm. The open area on my temporary booth is about 4 x 7', meaning my fan should be at least 2800 cfm. So even though my fan may seem large at 1200 cfm, it's not. I'm not sure I follow what your friends at work said about lowering the temp. in your shop. All I can say is that my 1200 cfm fan has minimal effect on the temp. of my shop even after spraying for an hour. Some of my makeup air comes down the chimney (I always turn off the furnace before spraying.), some comes from upstairs via the basement stairs. I think most comes down the chimney, but whatever might be coming from upstairs is already at 65 - 70 deg. If all of your makeup air were coming directly from outside, you might experience more drop in temp. than I have, but I still doubt it would be a problem unless you want to spray non stop for hours.
John
Member
Thanks. That's really helpful. My friends at work were agreeing with you; they note that because the fan will be blowing out, it won't lower the temp of the shop.
Do you open up another window besides the one with the fan? I've read several places that you should, thought I don't think I have to.
Contributor
That's kind of funny how your co-workers thought the temp. wouldn't change because the fan is blowing out. It doesn't matter if the fan is blowing out or blowing in. To blow out there has to be makeup air coming in. To blow in there has to be air leaving the house, somewhere. Same difference in terms of heat loss. In my case, I don't have another window in my shop that I can open, so the makeup air comes down the chimney, some probably leaks in under the sill plate, and some comes down the basement stairs from upstairs. If you have another window in your shop that you can open that would work. If not, you could open a window upstairs. The benefit of the using an upstairs window is that the air will be pre warmed as it makes its way to your shop so the temp. in the shop will drop more slowly than if you let outside air directly in through a basement window. The only way to find out what works best is to try it. In any case, you have to let makeup air in somewhere or the exhaust fan won't operate at its rated CFM. The tighter your house and the greater the CFM of your fan the more important it is.
John
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