HVLP: pros and cons? - created 11-10-2008

Burnside, Paul - 11/10/2008.11:48:30
Black Watch Musical Instruments

So I'm looking at some new spray guns, and I haven't been able to get the straight poop on normal vs. HVLP guns when it comes to spraying lacquer. Anyone care to chip in their two cents? Thanks.

I used a regular spray gun for some time, then switched to HVLP ( a Croix). There is still overspray, but not nearly as much finish is wasted as before, and I don't feel like I'm walking in a fog of nitrocellulose and acetone. The compressor warms the air, too, which is nice when spraying outside on colder days.

One thing that I don't much like is the large-diameter hose that has to be handled..but that's a modest complaint. Binks and (I think) others make conversion guns, now, that take high-pressure air from a regular compressor and change it to HVLP right at the gun; I haven't tried one of those, but it might work well and eliminate the bulky hose..

I use a inline pressure reducer with my HVLP gun. I would suggest going to a automotive paint supply store (not a car parts store) they usually have a good selection of guns and are good at explaining the differences. I used to paint cars and the old guns required a lot of pressure (100-125 psi) where the HVLP do the same at 15-25 psi. You dont notice much difference in the spray pattern but a HVLP has a lot less overspray and your compressor does not have to be as large or work as hard. You can find discount guns at places like Harbor Freight but you get what you pay for.

The HVLP guns that run off of compressors are excellent for lacquer spraying. They work as well as or better than the old high pressure guns.

I have read that conversion HVLP guns (the type that run off an air compressor) have slightly better atomization than a standard HVLP. My conversion gun gives a very soft and misty spray pattern that has very little bounce back.

Could you all post your spray gun manufacturers and model numbers when possible? I'd like to have some guidance before buying. Thanks.

I've been using this HVLP Detail gun From Harbor Freight lately and it's been doing a great job. Just the right size for guitar finishes.

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=46719

(No, I'm not kidding)

I've actually seen a lot of good reviews on that one. What rating is your compressor, and how are you running it? Thanks.

I have that gun and it was not worth the $14 I paid for it (on sale). If you ever use a gun such as a IWATA or a STV you will never spray with anything else. The atomization is so much finer and the spray patterns are so nice you"ll be amazed at the first time you spray. Your buffing time is greatly reduced by the quality of the finnish. I would say spend the 100-200$ you wont regret it. I use a STV primer gun and when i spray the only buffing and sanding I do is to fix mistakes IE:runs and the occasional dust spot. If more luthiers and woodworkers knew how these guns perform, Rocklers, woodcraft and harbor freight would never sell another gun.

I also use one of those cheap guns. I didn't get mine at the same place but I didn't pay much for it, it's a jamb gun by Campbell-Hausfeld.

A lot of luthiers use those cheap guns, and they get good results, and I do too. There's more than one way to do it Paul, and just because you didn't have a good experience with it doesn't mean that no one else ever can. I do agree with you though that the better guns are superior, I just don't need it.

Yes I see your point I'm a little prejudice when it comes to guns since I used to do it for a living and fixing problems cost profit. ( In body work theres very little), I gave my dad that harbor freight gun that he sprays water-based varnish and he has had good success with it. He sprays doors with it and the general finish brand covers very well and hides a lot.

From what I've read, there are a couple of models sold at Harbor Freight, they look exactly the same but one is labeled "HVLP" and the other isn't...they perform very differently and some folks have been upset about that.

I used to use a cheap "HVLP" gun from Grizzly and thought that it was quite sufficient. Somehow, I got the urge to upgrade. I bought an Asturo SX. Once I got the new gun dialed in, the difference was amazing. It really cut my leveling and buffing time. Runs are much more infrequent. Sometimes, I can spray clean enough that the surface almost doesn't need leveling. (I usually spray USL. It also sprays the KTM-9 very well.) I use a compressor with the regulator set to 40-45 lbs. when the trigger on the gun is pulled. The gun definitely won the "Worth it" award from me.

I've got the Fuji Q4 Pro system (HVLP - the Q4 stands for quiet 4-stage turbine). I've finished five guitars so far with it, and no complaints. I have no experience with compressor-based systems, and so cannot offer any comparisons. The large hose isn't an issue for me. I did purchase the gravity feed option and am glad I did. It makes for filling the cup and cleanup after very easy. You can adjust the spray pattern at the nozzle, as well as fluid volume and air volume at the gun itself. There are a variety of nozzle sizes (I use the 1.4mm needle). I'm shooting nitro. So far, so good.

I would say spend the 100-200$ you wont regret it. I use a STV primer gun

Could you post a link to STV? I'm currently using a cheapie door jamb gun which gives very good results but it would be nice to reduce the overspray in the basement to avoid that layer of dust everywhere.

As I'm looking, I can find HVLP conversion guns for $250+ which is more than I want to spend and around $30 which others mention may not be worth it. Can we post some links to guns in the $100 range that are a true upgrade to a $30 gun?

TIA,

If your looking for a slight upgrade to a $30 gun your best bet is ebay I found several devilbiss guns for $79 dollars. I would go with a primer gun due to the vicosity of wood finishes. I would strongly suggest finding a automotive paint store and talk to a sales man. The prices I've seen on the internet seem a bit inflated.

Hi there folks. I changed over all my spray guns several years ago. We were using a conventional Binks Model #2001 guns, and had even owned the top end SATA guns (over $1000.00 per gun). We are now using the Binks Mach 1SL HVLP Guns. We currently employ 6 of them in our finishing operations. We also have tried several Knock off cheapo guns. What I have found is this: With the HVLP Guns, we are realizing about a 75% transfer efficiency rate with the finish. However, the atomization is not quite as good as a conventional gun (with which we were getting about 30% transfer rate) The transfer rate is the amount of finish that actually hits the piece being finished as opposed to ending up in the filters. However, the difference in atomization would only be noticed by someone that has used the Conventional gun extensively as this particular model of Binks HVLP gun does it's job very well. We have had a 50/50 success rate with Cheaper guns. Some don't work well at all, and others have done an adequate job. If you require something for the occaisional spray job, go with the inexpensive guns. It'll do the job and you'll have to spend a little more time, wet sanding the finish. But if you are using the gun on a weekly or daily basis, spend the money on a decent setup. The time you spend trying to fix the guns or dealing with the problems arising from poor performance will more than pay back the cost of the gun.

After considering the following:

1) Everyone's opinions on here

2) The fact that I spray 3-5 finishes per year

3) The state of the economy in general and mine in particular

I went with the Harbor Freight model. Picked it up today, fiddled with some different mixtures and settings, and used it to spray a black coat on a bass I'm finishing up. I'm pleased with the result thus far...less lacquer wasted and the texture looks pretty good for now. I'll post followups as they develop.

Hi, I´m interested in that Harbor Freight gun.

is it stainless steel and do you use it for waterbase lacquer?

Thanks

Anders