Supplied Air Alternative???

Basically the hobbyair and others similar to it are nothing more than a high volume low pressure turbine probably no more than a two or three stage system where the output is somewhere around a few psi and maybe 5-8 cfm, I think. If so, has anyone ever tried to modify a low cost turbine air pump from let's say a H.F. HVLP paint system for this application? The only downside is that the air is quite warm out of one of these compressors.

Another option which would work quite well is using a old cpap machine which is used for folks who suffer from sleep apnea. This would work quite well if one could find a used one at a reasonable cost.

Other options are to use air from the main compressor but that requires a lot of filtering and I think that it maybe the least desired approach. I just don't like the idea of using air out of a tank where a bunch of nasty things may be lurking, but let's talk about that also.

Lastly, we have the option of using a vacuum cleaner blower. It too is a low pressure high volume system. Has anyone played with this approach?

While we are on the subject can we also discuss your experiences with face masks and hoods.

As you can see, I am a beginner and am trying to get some ideas and approaches to this very important subject.

What I've done is to gang 4 of theses old steel tanks together in the corner of my painting area and run them through about 50 ft of line in the face mask. I was able to get ahold of the pac's for free. I ended up buying the line and 4 way valving on ebay for about $80. Tanks need to be hydro'd every 5 years. Last time I had it done it was like $30. I get the tanks filled at my local dive shop for $5. I get about 25 min of air from a single tank. I run two tanks at a time. When those go dry I switch to the other two in the gang. That has been plenty of air for any of my projects so far. I think I have about 10 tanks in all with about 8 or so I keep in service.

That's a great question. It's also one of the most important when dealing with a fresh air system. Here's how I do mine: I always paint outside. I place my supplied-air compressor outside about 60-70 feet away from where I am spraying and around a 90 degree corner of the house. That location is also generally upwind from the spray area. The arrangement works fine for me. Which brings up another argument for exercising care in determining how much hose is needed between the air supply and the mask/hood. Some of the turbine systems have limited capability in that area so anyone should plan out an expected suitable air supply location before deciding on equipment purchase. The "official" turbine hose can also be quite expensive, which is another reason why I prefer the non-lub, tankless compressor. I run 100ft of standard, inexpensive, 3/8" pvc airline hose and believe my system would work just as well if I decided, for whatever reason, to add more.

Rod

I'll respond since I've been successful in "cobbling" together a workable supplied-air system. I also understand the desire to "make do", if possible. When I put mine together years ago, supplied air was not that common and commercial systems were all very expensive. I first purchased a commercial full facepiece for a mask. I tried using it supplied with air from my regular compressor. Two big problems with that - one, my compressor was not large enough to supply enough air continuously to both the facepiece and the spray gun at the same time. You should have 4 cfm for a facepiece and 6 cfm for a hood to have an adequate breathing air supply. Second, I did not have any filtration devices for breathing air and I noted a distinct taste of oil in my mouth. This was totally unacceptable to me. I then purchased an oiless, tankless compressor to be dedicated to supply air to the facepiece. It wasn't an "official" breathing air compressor. I used (and still do) a 1hp Campbell Hausfeld portable air compressor. I backed the built-in pressure regulator off such that it had no effect and pressure would build up only as needed to overcome hose resistance and supply the maximum amount of air that the compressor could produce under those conditions. I left the pressure relief valve in place for safety. I used 100 feet of standard 3/8" ID compressed air hose between the compressor and the facepiece. I verified that I had enough air at the mask by holding my palm close to the exhaust port on the mask while breathing in at the same time. By feel, I confirmed that I always had an outflow of air which also confirmed that there was a positive pressure in the mask, relative to the ambient air, even when breathing in. It's very important that a postive pressure be maintained in the mask at all times to prevent any infiltration around an imperfect face seal. This is a system that has served me very well for a lot of years.

That said, I don't think you will save any money going this way unless you can utilize something you already have available. The rise of relatively inexpensive turbine systems such as the Hobby-Air and the other one on Ebay in recent years has made cobbling together some kind of decent system of questionable economics. If you have to buy the parts, I don't think you can do so for the price of those turbine systems. I prefer a compressor-supplied system because the air never gets hot and the hose is much smaller and easier to drag around. It also can be extended significantly in length, as needed, w/o adversely affecting the airflow.

I have no use whatsoever for the systems you can buy that process the air from a regular compressor. For one thing, they are expensive to buy and to maintain, especially if you have the recommended CO monitor/alarm equipment. For another, I am opposed in principle to filtering out bad stuff when an alterative is readily available. I think it is far safer (and cheaper) to use fresh air in the first place than to rely on filtration of questionable/bad air. There just is no need for that, even if the shop compressor is big enough to supply everything simultaneously.

The only issue I have with my system is the compressor is very noisy, as most of the portable, non-lubricated ones are. But it's a relatively short duration and acceptable to me for the great benefit it provides. You can get a commercial system that operates on the same principle and that is quiet but you are looking at a minimum of about $800 or $900 for that. The things that I think are most important are 1) a good fitting full facepiece or hood, 2) a supply of air that is sufficient in quantity to provide a positive pressure in the mask or hood at all times, 3) a source of air that doesn't add any nasties to the air itself, 4) the ability of the source to supply the needed quantity of air through whatever connects the hood to the air source over the longest distance needed for the job and 5) a location of the source where there is always fresh, breathable air available and there is no possiblity of ambient contamination. If you need to wear glasses when spraying, then you should look at a hood and not a full facepiece.

If you go the route I did by assembling purchased parts yourself, it is likely to cost at least as much and probably more than the Hobby-Air or the "Breathe Cool" Ebay commercial units.

I don't think there is a cheap, quick fix here that I'd want to use. $400 is not a high price to pay for a ready-to-use safe breathing air system. You can spend more than that just for paint on one job. If you are only thinking one job anyway, think about re-selling the system on Ebay after you are through with it. There is plenty of demand for something like that and you'd likely get at least half your investment back. That's what I'd do for a one shot deal. If you are going to be painting into the indefinite future, then the investment is well worth the full cost, IMO.

Rod

Another quick question. I am planning to do both sandblasting and painting. What are your thoughts on getting two different hoods or would one for both applications suffice? Also, if one were to use a good quality positive air flow hood would you also need a face mask? Are latex gloves acceptable for handling paints or do you need different types. Sorry for the learning curve questions, hopefully, someday I will be able to impart knowledge to another learner.

Thanks,

Mike

Thanks for the very informative reply, you guys are great. I have no problem buying a fresh air system and yes, I probably would sell it on E-Bay when I no longer needed it. After many years of absence, from the days of lead,lacquer, and siphon guns, I want to refurbish and paint a bunch of JD garden tractors that I have collected and needed your inputs on this important subject which we never worried about years ago. I have much to learn anew now and seek your advice and thank you accordingly for it.

I now need to look at face masks and hoods, what are some good sites for this information?

Mike

My full facepiece was made by Pulmosan Safety, which is no longer in business. SAS is a major supplier of hoods, masks and systems. Hobby-Air also sells the individual masks and hoods as well as the complete systems. I don't know if the Breathe-Cool products are sold individually. Neoterik is another one. There are others also but those are the ones that I'm more aware off.

I have no experience with SA hoods so hopefully CNKS will respond concerning the hood and sandblasting. I wouldn't expect you'd need two supplied air hoods. The issue I see with using one for both painting and blasting is protecting the faceplate from the blast grit. I don't know if the acrylic peel-off paint protectors are suitable protection when used for blasting. CN would know. If you use a supplied-air hood for blasting, I see no need for a facemask in addition to it. The blast "hood" that I have has no supplied air. It's only covers your head and protects your eyes, face and hair from grit. It has no respiratory protection.

Regarding gloves, my experience with latex has been poor. Nitrile is much better and is generally recommended instead of latex. Latex goes to pieces very rapidly when exposed to reducer solvents. Nitrile will too but it lasts longer. You can get a box of 100 nitrile gloves for about $15.

Rod