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Thu Jul 20, 2006 8:03 pm

evilbox

compressed air that is expanding cools! physics 101
mike

Sat Jul 22, 2006 6:56 pm

Uh... so what's your point?

The air produced by the electric turbine motor is warm to hot. It is being further compressed into a 1" hose. It is then being forced thru a very small needle at the gun. The air/paint/reducer/catalyst mixture sprayed from the HVLP turbine gun is much warmer than that produced by a standard compressor based system (which is basically room temperature). When you mix your paint you've got to account for this increased temperature and associated evaporation rate by reducing your paint at least 10 percent further than the paint manufacturers specifications. If there are newer HVLP turbines that actually cool the air before it reaches the gun (and I'm not sure how they would) then you would mix your paint in the conventional way.

But what can I say... buy an HVLP turbine unit, use it about 200 times, go through all the trial and error, make the introductory mistakes that I made, figure out exactly how the paint has to be mixed to be sprayed with an HVLP turbine, and we'll talk. Or you could just listen to what I said and reduce the paint an additional 10 percent. The choice is yours.

E.B.

Sat Jul 22, 2006 8:04 pm

MkRiley,

According to this link, you maybe right about the newer machines cooling the air prior to delivery to the gun. Although I'm not sure if I'm interpreting thier statement correctly. I have used this unit also, and it works great. TIP makes a nice unit. A bit pricey, but very nice and parts are easy to order thru them...

http://www.tptools.com/product.asp?base%5Fno=TP90H...HN09G79FW1

NOTE: Please don't contact Campbell Hausfeld with technical questions about thier turbine sprayers because they will tell you they can't be used for automotive paint, but I know they can because I'VE USED THEM. Campbell Hausfeld is either ignorant of the fact that thier machines can be used for this purpose OR they don't want the liability that goes along with spraying automotive paint. Several people have contacted them (and P.M.'d me) concerning using thier machines for spraying automotive paint. CH says you can't. I say you can. They've never used their machines for this purpose. I have. Therefore I can say from experience that thier machines can be used for this purpose although they will probably void your warrantee if you do (assuming you tell them you used it for this purpose :wink: ). If you're still leery of using the CH machine, you can always order the machine in the link above or one like it.

E.B.

Sat Jul 29, 2006 3:45 pm

Evil Box , Your first statement is correct . There is no turbine that cools the air before it gets to your gun.
I'm with you on the turbine sprayers. I love 'em. You do have to get used to them as far as thinning goes. I usually go the next higher temp reducer to slow the drying down enough for the paint to flow out .
I've been spraying anything that can be sprayed since I was 17 . I'm 50 now(so I got you beat , in years anyway) :D

Wed Aug 02, 2006 5:54 pm

If you experienced turbine users were to purchase a new spray system
which manufacturer and model would you buy.
I've taken my 66bus out of the mothballs (16yrs in storage) and have been doing body work and have been contemplating painting it myself.
All my old spray equipment needs to be replaced anyway. I've seen some impressive jobs painted with turbines and I'm willing to give it a try. I just want to purchase a quality unit from the beginning. Any imput would be appreciated.
bp/sc

Wed Aug 02, 2006 8:24 pm

I have been using an Accuspray turbine system and suction paint gun on my project and I have to say I'm not totally happy. I think there's a lot of good things about the turbine system (portability, low noise, can use on any sprayable paint, etc.) that are good, but I have some problems which may be manufacturer specific. I've only used this Accuspray 10 series gun and 3 stage turbine so I'm not an expert. I paid about $400 for a 10 year old lightly used unit off ebay, so perhaps they've corrected some of the faults.

Biggest problem - dealing with the drips. I think I may have been able to get around this if I had a new gun, but for some reason, my gun dripped like crazy. I have been able to get the paint to lay down very well with proper reduction (esp. on high build primers reduction is crucial) but the gun leaks badly. My theory is that the plastic body of the gun has warped from too much solvent. Don't know if this is possible, but either way I'd feel more comfortable with a metal bodied-gun. A gravity fed gun that doesn't need a hose from the gun to the cup would probably be the best solution. They do make a gravity fed version, but it's about $100 more. The paint leaks out the back of the needle too pretty badly. Maybe less with a new gun.

Reducing the paint is the key to success with these things. Especially in this hot weather. I have been thinning my epoxy primer almost 30% (for use as a sealer) in this weather.

Cleaning the guns is more difficult as well, IMO. The plastic bodied guns arent supposed to be in solvent for too long and also are heated by the hot turbine air. This makes the paint cure faster, etc., so it generally gets nasty quick.

I would like to buy a new gravity fed accuspray gun at some point and see if they were able to fix some of these issues. However, at $350 or so, it's kind of hard to not buy a Sata or Iwata that you *know* works.

Sun Aug 06, 2006 8:44 pm

Sounds like you've got a defective gun. Accuspray has been around for a while. Their stuff used to be a bit overpriced, but I guess they work okay. I've never used one. Might want to try ordering what you need from them and give it another go.

Beep,
Try "Tip Tools". They advertise in Hemmings Motor News and make a pretty good unit.

www.tptools.com

Wed Aug 09, 2006 2:31 pm

Yeah I was going to give them a shot on my next project evil box, accuspray is quite overpriced. Their gravity version of the 10 series gun is about $350. I can get a turbine and gravity gun from tptools for just a little bit more.

Good thing is the accusprays have pretty high resale value.

I did buy a harbor freight Iwata knockoff, supposedly only 5.9 cfm, so that should get me through this project. Harbor freight P/N 90977 on the website. I'll test it out this week and post some pics.

Sun Aug 27, 2006 9:15 pm

Accuspray Is a good one of the best. I would buy a rebuild kit and get some spare tips and large and smaller caps. Accuspray makes many many diffrent size tips/caps for the paint you want, They also sell theirs for use with auto paints ect. I have 4 of ther guns and none has ever failed. The Gun might just need a good cleaning, Take all the screws out and seperate the two halfs and clean.

Thu Aug 31, 2006 1:47 pm

I just picked up a CH 2500. Gently used, but with no gun. Can I get some fairly cheap recommendations on what to get? This gun won't be used to do final finishes on anything, just to get me trained on what to expect.

Edit; Gravity or siphon.

Sat Sep 30, 2006 2:39 pm

I bought the Campbell Hausfeld hv2500 turbine sprayer, works good. I used a small spray circle pattern to do this small part. I painted it with black tremclad rust paint from hardware store. This kind of paint took a long time to dry and it always stays kind of soft, but apparently very durable. Just following the instructions for thinning the paint and setting up the gun that came with the turbine sprayer unit, seemed to give good results.
I think with automotive paint and thinning it out the extra 10 percent; using these spayers would give good results.
From what I read in this thread, it sounds like hvlp turbine sprayers can give really good results. And it sounds like there a lot less hassle to set up and easier to use, and less expensive.
I would like to try painting a whole car with this hvlp turbine sprayer.

Fri Oct 06, 2006 8:59 pm

DurocShark wrote: Ok, it's been like 20 years since I painted with anything other than a rattle can or a roller. Last year I picked up one of these from Harbor Freight:

Today I finally got to try it. I used it with Rustoleum primer on some rusty sanded metal. Figured this is where to use it to get used to using a gun.

I'm really happy with it! The spray was consistent and easily controlled. Way better than rattle can IMHO. I was able to lay it thin or thick, however I wanted. I thinned the Rustoleum 4:1 with acetone and that seemed to work well. Little orange peel. The paint flowed nice, but to be honest the pieces are laying flat on the ground. Heh.

Anyway, just thought I'd share. :)

---------------------------

UPDATE:

I painted the sliding door covers on the Guac with this and that same Rustoleum. I'm happy with this gun.

I haven't done any wetsanding or anything yet. They've been on the bus for 4 days now, after drying in the garage for 2 days.

and

(Forgive the GIFs instead of JPGs. I didn't pay attention to what photoshop was saving... sigh.)

other than spooks opinion on this sprayer, does anyone else have an opinion on this HVLP?

Fri Oct 06, 2006 10:40 pm

Fri Oct 06, 2006 10:57 pm

guess not. #-o

Sat Oct 07, 2006 12:41 am

Well, if you're interested, it's on sale at HF for $30 right now.

Sat Oct 07, 2006 1:01 am

kenzo42 wrote: Well, if you're interested, it's on sale at HF for $30 right now.

well i just wanted to see if there were anymore positives/negatives on this product. as i see, the only guy that has used this product in this post is the guy that started it in the first place. i do my painting the old fashion way with a compressor. was thinking of buying it so my kids can start to practice with painting. would like them to use it on their bikes and other little things. i feel this machine would be a good starting point and would introduce them to the in's and out's of painting. reading can do only so much but hands on experience will do wonders. if they screw up or break the machine in some way, we can just throw the hvlp away with no worries.

Sat Oct 07, 2006 1:27 pm

Evil Box wrote:

Quote: but I know they can because I'VE USED THEM. Campbell Hausfeld is either ignorant of the fact that thier machines can be used for this purpose OR they don't want the liability that goes along with spraying automotive paint. Several people have contacted them (and P.M.'d me) concerning using thier machines for spraying automotive paint. CH says you can't. I say you can.

Could you confirm whether or not you've used the CH machine for urethanes?

thanks...

Tue Dec 05, 2006 6:29 am

Sorry, I haven't posted here in a little while...

Let me explain why you can absolutely spray urethanes (or any paint for that matter) with an HVLP turbine system. First of all, the only difference between an HVLP turbine system and a conventional system is the compression method NOT THE GUN. The actual HVLP gun in a turbine system is exactly the same as a conventional HVLP gun except for the hose attachment from the turbine compressor to the gun. The turbine system uses a larger hose than a conventional gun, that's all.

Therefore, the only difference between a turbine system and a conventional system is THE COMPRESSOR METHOD. The conventional system uses a conventional compressor which is large enough to keep up with the demands of an HVLP gun (which requires quite a bit more volume than a conventional gun). The HVLP turbine system replaces the large conventional compressor with a small electric turbine motor which produces the same exact pressure at the gun. Therefore, there is ABSOLUTELY NO DIFFERENCE between conventional HVLP spraying and HVLP turbine spraying, except that the turbine is actually a better method because it dries the air before delivery AND you never have to wait for a conventional compressor to "catch up" in the middle of a paint job AND you can never have an oil contamination problem because there is no oil in an electric turbine motor. When spraying a car, things have to be just right. Air temperature and the purity of the air must be as clean and pure as possible. Why complicate matters by using a standard compressor which will only introduce oil and water into the picture? Two things you absolutely NEVER want when spraying a car. Given the choice between the two, I'd choose an HVLP turbine system every single time.

Hope this helps,
Evil Box

Tue Dec 05, 2006 8:29 am

thanks for the reply evil box!

Thu Dec 07, 2006 9:12 am

Nice info there, good to see you still reading this thread Evil Box. I just picked up the Harbor Freight deal like the original post and plan on doing my car with it soon. Yes I will be using Urethane and doing a bc/cc. I hope to start at least the primer this weekend, I will post some reactions and pics after I start.