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Harbor Freight HVLP options?

PostPosted: Mon Feb 20, 2006 3:57 pm
by greasywheats
Want to be able to spray my TD with spar varnish using a HVLP system,,,But,,,,I am on a budget here. Wondering if any of the spray specialists on the board have any experience with the Chicago Electric HVLP turbine system (pg 33 of the recent catalogue)? :thumbsup: :thumbdown: Seems like a decent option....it says it sprays varnish. I guess my other option is to buy a small compressor and gravity fed guns like I saw posted here earlier. I am not looking for a mirror shine marine finish, just something that would be roughly equivalent to doing it by hand (roller with touch up) but much faster. HF also has rechargeable and corded general spray guns...any experience with these?
Thanks

PostPosted: Mon Feb 20, 2006 4:01 pm
by Chris C
Maybe others will disagree with me, but I believe spraying systems are one of those "ya get what ya pay for" areas. Besides, varnish is easy to brush...................and brushes are a lot cheaper than a spraying system.

PostPosted: Mon Feb 20, 2006 4:14 pm
by greasywheats
Chris - i totally agree with the whole "you get what you pay for" concept generally (and the "you pay for what you get" one too). I just don't know about HVLP systems (or non-HVLP for that matter). While I'm sure the $600 HVLP turbine systems will also handle finishing fine cabinetry, that's really not the level of quality that I need in this application (although I do a have a couple bookcases that are about ready to stain/finish). I am basically looking for an option to shorten the varnishing stage of my build (and make it more enjoyable- I hate painting) at a reasonable price. Just trolling out here to see if anybody says it is a total piece of S*%#, or if it will hold its own. Thanks for the reply!

PostPosted: Mon Feb 20, 2006 4:23 pm
by madjack
greasy, we have both a regular sprayer and an HVPL system from HF...they are air powered and cheapies...they both do a very adequate job...also had a couple of Wagner electric power sprayers, they were ok but not much control on the spray pattern and tended to collect overspary on the guard and drip so you had to keep the guard wiped while spraying...have also borrowed a Campbell-Hausfeld electric HVLP system and found it put out way to much paint for smaller jobs as it was intended for house painting
madjack 8)

PostPosted: Mon Feb 20, 2006 7:43 pm
by tk
Hey Greasy,

You might want to reconsider the whole idea of spraying varnish. I'm not much of a finish man but the common wisdom is that bubbles are the big enemy of varnish. Once there, they're hard to eliminate. Obviously, spraying mixes air and finish in spades, bubbles being the expected result. That's why varnish cans always caution to "stir not shake." You might instead consider a water-based polyurethane. I have sprayed it with reasonable results.

Best,

Tom

PostPosted: Mon Feb 20, 2006 7:52 pm
by greasywheats
TK- thanks for the reply...I figured that an HVLP system would atomize whatever you put through it so that bubbles would not be too much of a problem. Am I off base with that? Thanks!

PostPosted: Mon Feb 20, 2006 8:05 pm
by halfdome, Danny
Gravity fed HVLP guns that go for around $100 are great in my books, it's all about your technique and air pressure. Take your time, use a tack rag between coats, collect & remove the water in the line and have a hose 25 feet long after that otherwise you could get moisture in your finish and fish eyes are no fun.

PostPosted: Mon Feb 20, 2006 8:08 pm
by madjack
...I'm a spray man myself and while I have never sprayed "varnish" I have sprayed many a gallon of urethane, both solvent and water based and have never had bubble problems from spraying...bubble problems seem to be a cheap bristle brush problem...if not spraying, I like to use a foam roller and take a foam brush and "tip" it out if needed...another note when spraying...thin your material about 10% with thinner or water depending on the base...it'll spray beter and lay flatter...of course I usually thin when brushing also.................
madjack 8)

PostPosted: Mon Feb 20, 2006 8:23 pm
by greasywheats
Thanks guys...I have seen the reference before to water in the lines when using hvlp and can understand how that would cause problems under the finish. Is the water a result of using an air compressor (i.e.- from the tank)? Would using a turbine rather than compressor driven hvlp unit eliminate that problem? Then I'd just have to focus on getting the finish sprayed evenly right?

MJ- I was thinking of thinning the first and 3rd Varnish coats like 75%/25% or 50%/50% (per someone else's suggestion). BTW- I am planning on using Marine Varnish because I heard somewhere that Marine varnish (3 coats) will not dry and crack as quickly as polyurethane does. I have seen plywood with poly where it has dried up and cracked leaving those nasty ridges...any ideas from your experience (or others')?
tHANKS! :applause:

PostPosted: Mon Feb 20, 2006 8:41 pm
by madjack
greasy, I can't say I have had any problems with poly...keep in mind that successive coats need to be applied either close together of after complete curing...I think my habit of thinning may have possibly helped...over the last quite a few years I have become a big fan of MinWax ClearSheild poly. It is a heavybodied outdoor rated poly and we have had very good experiences with it....when thinned poly does not put down as heavy a coat and seems to soak into the wood better...also spraying does not put down as heavy a coat...you may have to spray a couple of more coats to get as "deep" a finish but you get a better finish...for a water based poly used in interior applications, MinWax Polycrylic or a comparable quality product works well...ClearSheild will have a slight warm yellow cast to it when cured and Polycrylic will be just about perfectly clear
madjack 8)

PostPosted: Mon Feb 20, 2006 10:30 pm
by halfdome, Danny
Water in the lines has something to do with the dew point in the air that has been compressed and it may take 25 ft for it to become liquid. They recommend a water trap at 25 ft and a 25 ft or longer hose to your spray gun whether it be conventional or HVLP. If your air pressure is too high you can have a host of problems. Danny

PostPosted: Mon Feb 20, 2006 11:02 pm
by Laredo
If you want to get a quick lesson in how the water gets in the sprayer lines, grab a can of canned air and spray it for about two full seconds. Now feel how cold the can is?

That's how cold the air in your lines will be. Unless you're working in air too cold to dry your project, you're going to have a significant difference in the ambient air temp (and in all likelihood its humidity) and that of the air coming out of your equipment.

The warmer air holds a lot more water. The colder air will chill your mixture and/or surface and encourage condensation.

PostPosted: Mon Feb 20, 2006 11:54 pm
by asianflava
I worked at a paint shop in FL, we did mil-spec painting and screen printing. Our shop had a hard PVC line from the compressor to the paint booth. We had 2 drain drops, one after the compressor and one before the booth. We also had an air/liquid separator inside the booth and a disposable drier on the gun itself. We would drain everything including the compressor tank every night. We would get about a quart of water every day.

It may be a bit of overkill but when spraying in the mid 90's with 90% humidity, you have to be prepared. The only shure way is to use a refrigerated dryer which costs big bucks.

PostPosted: Mon Feb 20, 2006 11:55 pm
by greasywheats
So if the HF turbine HVLP only has a 15' hose, i might have trouble with water in my finish...

OK- option #2 is to buy a air compressor and HVLP gun from Harbor Freight. I don't mind doing this since I plan on someday adding a brad and finish nailer to my tools, so.... Can the Harbor Freight masters on the board tell me what size compressor (HP/ PSI) is the minimum to effectively spray varnish and/or polyurethane and run your average small nailers??? I know, this is probably one of those "depends on your needs" type questions, but what are the minimums I should be looking at? Any recommendations on specific guns? :?

Thanks for all the help folks!

PostPosted: Tue Feb 21, 2006 8:58 pm
by Jim Marshall
Just a heads up, Harbor Freight 20% discount coupon is back and is good until the 25th of February. That may help defray some of the cost on the HVLP.