Replies

1. 
   SgianDubh | Jun 20, 2003 10:09am | #1

   butch, About US$100 or a bit less for a passable spray gun, and you'd need at least a small compressor at about the same price-- but that would really be pushing a dinky compressor to its limits.

    About $20+ for a gallon for oil based poly, and maybe $10 for mineral spirits to flush out the gun and to thin out the poly a bo'hair-- about 15%. Or you could use naphtha to thin with instead-- ~$7 a quart. 

   Then because of the stickiness of the overspray, you might need to consider a good fan or two to suck it out-- free from attics all over plus a bit of boxing and chicken wire, ~ maybe $100 if you buy all new materials excluding the fan motor and blades.

   And lastly some abrasive paper to rub down between coats. If you're going to get really fussy, you might need to buy additional abrasives like wire wool, pumice and/or rottenstone, and some oil to do some rubbing out-- about $40. Slainte.  

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1. 
   Kevin | Jun 20, 2003 06:06pm | #2

   An el cheapo gravity gun might be the way to go on a budget. They need less air than a cup gun - meaning that there'd be less overspray as well as less taxing on the capacity of a small compressor. Harbor Freight sells plastic gravity guns (basically a disposable gun) for about $12.00 last time I checked. You get what you pay for in terms of quality. But... with a clear coat that's not as critical as it would be if you were trying to spray color on a car or something like that. One of my gravity guns is a cheap Taiwanese copy of a top-of-the-line SATA. It retails for right around $100 and is available all over. I've seen it badged many different ways. But, it's the same basic gun which is probably made in the same factory. Do a search on EBAY using gravity gun as the criteria and you'll see many versions of this same gun. If you ignore the badged name and just look at the gun, you'll see that most of them are the same damn gun. LOL

   Regards,

   Kevin

1. 
   SgianDubh | Jun 21, 2003 06:06pm | #6

   Good point about the gravity fed gun, Kevin, and not overtaxing a small compressor. To get started economically that might be a good way to go. And as has been pointed out elsewhere, even a fairly small compressor can have lots of uses apart from spraying

   And thanks to the Rev for bringing up an oversight regarding a good mask-- yes those fumes can be nasty. Slainte.                                                                                                                    Website               

1. 
   Kevin | Jun 21, 2003 08:00pm | #9

   That Harbor Freight plastic Gravity Gun I mentioned previously... It runs off a blower enabled shop vac. No compressor needed. I'm sorely tempted to buy one just to see how it performs.

   http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=47482

   If anyone here has one or buys one... please post a performance update here. If (and that's a big IF) the thing performs reasonably well... it might be an excellent way for the D-I-Y'er to transition into sprayed finishes without having to spend a bunch of money.

   Regards,

   Kevin

2. 
   Joe_Fusco | Jun 20, 2003 07:45pm | #3

   Butch,

   You could always buy your poly in a spray can. . . About $10.00/can

   View Image

   
   

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   Edited 6/20/2003 12:50:53 PM ET by Joe Fusco

3. 
   theRev | Jun 21, 2003 07:29am | #4

   Butch,

   One thing which has been neglected so far is personal health considerations. Poly fumes/poisons will not be stopped by normal filter masks. A regular mask may take out the smell and lull you into thinking you're okay, but the really dangerous carcinogins (sp?) are coming right on in.

   If you are serious, look into a fresh air respirator. You can get one for the same price of a decent quality HVLP set-up.

   More info, drop me a line.

   Scott

1. 
   Kevin | Jun 21, 2003 07:50pm | #8

   Poly fumes/poisons will not be stopped by normal filter masks. A regular mask may take out the smell and lull you into thinking you're okay, but the really dangerous carcinogins (sp?) are coming right on in.

   Hmmm.... if by "normal filter masks" you mean properly fitted respirators with the proper filter cartridge for poly... I don't think I can agree. Provided the appropriate cartridges are being used... if one can't smell the poly then one is being protected from whatever the poly contains.

   The downside of cartridge respirators is that the onus is on the wearer to ensure that it is being used and worn properly. Facial hair/stubble, degraded rubber, improperly fitted/cleaned mask, improperly changed filters/pre-filters... all are things that can lull the ignorant into thinking they are being protected when they may not be.

   Regards,

   Kevin

1. 
   theRev | Jun 22, 2003 08:57am | #12

   Kevin,

   To be honest, I did not know about cartridges for poly. So, I hit google. This is what I found. It seems we are both right. Tell me what you think. I learned a bit out of this. Of course, it is the web, not a science journal. Me, I'll stick to my fresh air mask.Couple hundred bucks is cheap compared to the "hangovers" I used to get.

   http://www.woodweb.com/knowledge_base/Filtering_out_isocyanates.html

   Scott

1. 
   Kevin | Jun 22, 2003 07:55pm | #14

   Scott,

   I think that the forum technical advisor's comments at the bottom of your linked page are the most informative and accurate. OSHA only requires the supplied air respirators if the concentration levels of iscocynates are at or above a certain level. That said... isocynates are very nasty things that the person with a reasonable sense of self-preservation won't take lightly. While I maintain that an appropriately fitted, and worn (facial hair will prevent a proper seal of the face mask), respirator with the appropriate cartridges is sufficient and safe... there is no doubt that a supplied air system is the best of the best in terms of personal protection.

   I worked for a guy a number of years ago who was sensitized to isocynates. It's basically like having an allergy. When he sprayed anything with isocynates his eyes would weep as if he were crying hard. He had to keep a handkerchief handy and wipe his eyes every minute or so just so he could see what he was spraying. Not a pretty sight... Of course, he was a Ditto Head and Clinton was in office at the time. Perhaps he had just finished listening to Rush Limbaugh's version of the truth?  ;-)

   Regards,

   Kevin

   Edited 6/22/2003 1:20:10 PM ET by Kevin

2. 
   HowardAcheson | Jun 22, 2003 06:51pm | #13

   I think you will find that one part, oil based polyurethane varnish is no more dangerous than standard oil based varnish. The dangerous stuff is the two part true polyurethane coatings used by commercial finishers. They are entirely different stuff and very dangerous.

   That said, a good respirator should always be used when spraying even standard poly varnish. Even waterborne finishes contain chemical solvents that can be harmfull in an enclosed area. There is less odor, but the solvents are still in the air. Respirators are required for waterborne products too.

1. 
   Kevin | Jun 22, 2003 08:10pm | #15

    

   I think you will find that one part, oil based polyurethane varnish is no more dangerous than standard oil based varnish. The dangerous stuff is the two part true polyurethane coatings used by commercial finishers. They are entirely different stuff and very dangerous.

   That's true to a point. Some varnishes contain formaldehyde which is as bad or worse than isocynates. The Sherwin Williams wood finishing systems manual that I've got at work seems to treat formaldehyde as a greater health threat than isocynates - strongly suggesting the use of a supplied-air face mask whenever spraying a finish with formaldehyde in it.

   I'm a commercial finisher and from what I've seen the preferred finish for commercial coatings ranges from water-based conversion varnish to polyurethane and everything inbetween. However, precat lacquer and conversion (aka catalyzed) varnishes seem to be the most popular. Right now I'm in the middle of a project at work where the client has specified that I use catalyzed vinyl - which is an exceptionally durable, solvent resistant finish. But, it's also loaded with formaldehyde! Except for the reliance on vinyl resin... catalyzed vinyl is basically the same thing as conversion varnish.

   Regards,

   Kevin

2. 
   alias | Jun 21, 2003 08:15pm | #10

   i'll take that more info on the mask if you dont mind...... gracias'

1. 
   theRev | Jun 22, 2003 08:50am | #11

   Hi Bear,

   Here's the link.

   http://manofrubber.com/fastech.html

   Down at the bottom of the page are the "hobby" sets. I found mine to be more than adequate. I got the half mask set a couple of years ago. Then last month, cruising the local seccond hand store, scored a full mask, brand new, which fits nicely on the hose of my respirator pump. Good to go.

   Scott

4. 
   Telemike | Jun 21, 2003 08:16am | #5

   Buy a cheap gun, but don't buy a wimpy compressor.  Spraying is only one of the many tasks of the compressor.  You can blow (not a joke - it's very useful for blowing all kinds of dust and stuff), you can sandblast (for texture, for cleaning metal for welding and painting, and for etching glass), you can use air tools like die grinders, air ratchets, impact hammers, nibblers, shears, chisels, etc.  Get at least a two hp, a three is better.

   Oh, and did I mention that you can pump up tires?

5. 
   jtc | Jun 21, 2003 06:58pm | #7

   I spray with water-borne poly, so I don't have to worry about fumes, just particulate.  It's only slightly more fussy in the actual application, and cleaning up with water is so much easier (and cheaper).

   JTC