hvlp help (again, sorta)

As many words as are written in the documentation that comes with the Apollo system, I find the instruction lacking. For example, only the most basic of basics are covered on gun use.
So, I pull out one of my finishing books (Jewitt, I think) and see a tad more detail. OK. One thing that pops out is that when one changes the nozzle, one should also change the needle. Perhaps that's my problem.
Maybe I'm being really obtuse, and I obviously should've done more reading before I started using the thing. However, wouldn't a little bit more detail in the instructions be useful on the whole?
Is there a prerequisite step needed before trying to utilize the instructions that came with the product?
The diagrams in http://www.spraytechsys.com/literature/wag_lit/wag_pdf/HVLP_training.pdf cleared up a misunderstanding I had (in my head) about how exactly the air and "paint" flow thru the gun. So, I'm thinking the needle is the issue.
Anyway, haven't had the opportunity to test the needle theory yet, but am hopeful this will resolve the problem.
Any other ideas (just in case)?
Thanx Renata
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"Renata" wrote in message

Just that I feel your pain ... keenly at this very moment, AAMOF.
I just came back in from the shop after another round of spraying. Sprayed shellac on 3 of six chairs yesterday afternoon, started at 7 this morning on the last three, and plan on doing a large bench before sundown tonight.
All with an el cheap CH HVLP sprayer, sans instructions. My "setup" in the past consists of fiddling with the damn thing until it comes out right on scrap, then buffle off to shuffaloe. Thus far I'm always pleasantly surprised at the outcome, despite the cheapness of the tool and the lack of any clear instructions.
Right now I'm just hoping that holds up for the rest of the day.
Hope you fare the same ...
--
www.e-woodshop.net
Last update: 10/29/06
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Some way I got out of whack and replied to a newer message about your comments about Apollo's lack of customer service. You have my sympathy, and I am not being sarcastic.
When I bought my Fuji, I had to call customer support several times as I just couldn't get it to spray the way I thought it should. Without their help and their own personal experience in using their own equipment, the road would have been much tougher. I had never used HVLP turbine equipment before except at a demo, and getting the right aircap/pressure/viscosity was too was almost too much for me since all my experience was with high pressure equipment. The Fuji written information that comes with the system isn't much better than the Apollo, but their customer support is absolutely the best.
So - I am assuming the same problem exists. Yes? No? Spraying water when the trigger is closed (not depressed)?
Here is the easiest way to check for debris or poor fit of the needle-to-aircap.
- put your test material in the gun - close the needle valve completely, screw it down snug - turn on the turbien and give it some air
Does it spray material?
If it does, a few different things could be the culprit. If it sprays unevenly, it is probably debris, which we covered earlier. However, it sprays evenly, there are other distinct possibilites.
Each aircap requires a certain needle. In some cases, different manufacturers will use the same needle on a couple of different sized caps, but usually not more. I don't know what size aircap comes with the Apollo system, but I would guess somewhere along the lines of a 1.4mm. See if your literature gives a size, at it should be the same number stamped or etched into the cap itself. Now with the gun apart, check the needle and see if it is stamped with number or I.D. of some sort. See if it matches your literature on which needle goes with the cap. If the needle does not fit the correct aircap setup (you will have a stainless block that goes with the cap) then it will not seat properly causing it to spray. You may have a needle that is too small for the aircap assembly, and that would certainly explain everything if it always sprays.
Think of the gun trigger as it actually is; no more than a valve. The needle is the valve, and the gun block/air cap assembly is the valve seat. Make sure that you can see the needle tip move in the aircap assembly when you depress the trigger. It should move in and out of sight easily. If you don't see the tip of the needle even with or just outside the cap when the gun is not in use you may indeed have the wrong, or a damaged needle.
You should know that the needles on >>ALL<< of the HVLP systems are made from wire. It is a low end stainless tool steel of some sort, but in the end, it is just wire. They are not machined or milled from high grade mill stock to exacting tolerances. Each and every manufacturer of HVLP I talked to said they all used the same process to make their needles - wire. They just grind the profile on it to fit.
So, with that in mind, my Fuji guy told me that there existed a possibility that it was a defective needle when I had a problem with my gun. Nothing more. The needle that didn't seat properly in the gun wasn't really round and smooth, it just looked that way. I actually had this problem with mine on one aircap setup, and I used 100 grit, then 220 sandpaper to polish up the needle itself. I had a tiny leak on one setup, and a drop would form around the aircap when the gun was idle and under pressure. That polishing out with the sandpaper fixed it.
I guess the last thing I would check would be the tightness of the gun packings around the needle itself. They should just be tight enough to make sure the gun doesn't leak. If the packings are too tight, they will keep the needle from moving freely, which could keep it from seating properly.
Let me know if any of this works - or doesn't.
Robert
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Renata:
I am sorry that you are having a problem. I just called Apollo and they answered on the second ring. My Apollo unit is two years old and I have always had wonderful customer service from Apollo. I have talked with their customer service and technicians a number of times and have always been very pleased. Their salesman at the woodworking show is also very helpful and knowledgeable. I believe that perhaps they are not getting your message or the wrong person is. Hope you can get their help, they have always treated me with the highest customer servive.
Good luck, Build with Confidence, Mike
On Nov 8, 1:08 pm, snipped-for-privacy@aol.com wrote:

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Wed, Nov 8, 2006, 9:41am snipped-for-privacy@norealbox.com (Renata) doth queryeth: <snip> Any other ideas (just in case)? More power, more power. Arrrgghh!
JOAT Want cheap gas? Pull my finger.
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Renata wrote:

I have the gun and 3 needle sets. I bought it about three years ago and got the extra sets a few months later. There was no problem with me getting in contact with them then. You do need to change needles and tips as a set, maybe you bought a needle without the right tip? The instructions are basic but I guess they assume a basic working knowledge of spray guns. I haven't found the gun to be very different than any others. As always, you want to get the viscosity right for the tip and needle size, experimenting is how I do it.
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