Gasoline-Powereed Sandblasting Compressor Comparisons

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BillsBayou
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Gasoline-Powereed Sandblasting Compressor Comparisons

Post by BillsBayou »

Home Hobbyist: I'm still refining my sandblaster setup. I'd have the thing by now if Bullseye didn't have their 50% off sale for $1200 purchases (bye bye $800).

In my PREVIOUS THREAD the idea was to run an electric generator to power a 220v compressor. The shed is 50' behind my house and running a new power line to the shed is cost-prohibitive.

Now I'm thinking of using a gasoline-powered compressor in my lawn equipment shed, next to my larger workshop shed. Whenever I needed to do some sandblasting, I'll run an airline from one shed to the other.

Here's my list of gasoline-powered compressors which I am considering for the task. (Truck-bed and wheelbarrow compressors appear to be the only ones that run on gasoline in my price range of less than $1,000.)

Least expensive truck bed compressor:
Harbor Freight Truck Bed Compressor
$880 ($1099.99 minus 20%off coupon)
30-gallon tank, 14hp, 18 SCFM @90psi, 506lbs (230kg)
Downside: It's Harbor Freight; I'd have to build a special cart just to get to the small shed.
Notes: It's overkill but it's the biggest bang for the buck.

Comparably-priced wheelbarrow compressor:
Makita Wheelbarrow-Style Compressor
$979
10-gallon tank, 5.5hp, 12.5 SCFM @100psi, 190lbs (but has a wheel)
Downside: 10-gallon tank means compressor will be working longer; Higher SCFM rating means higher cost.
Notes: 12.5 SCFM @100psi is very nice. Even as performance fades over time, it won't drop below the blasting cabinet's needs any time soon.
A 10-gallon tank means the compressor will be engaged more often than a 30 or 60-gallon tank. One day, I may get a large reserve tank to take the load off the compressor.

If anyone has any experience with using gasoline-powered compressors, I'd love to get your feedback. Otherwise, I'm just going to put a desiccant filter on the sandblasting cabinet.
Brad Walker
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Re: Gasoline-Powereed Sandblasting Compressor Comparisons

Post by Brad Walker »

I have no experience with gasoline compressors (wonder how loud they are), but wouldn't want to do any sandblasting with a 10 gallon tank. Even 30 gallons is not that large, probably the absolute minimum tank size you'd want.
Warren Weiss
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Location: Richmond, VA

Re: Gasoline-Powereed Sandblasting Compressor Comparisons

Post by Warren Weiss »

Hi,
You can get a 60 gal. compressor at Home Depot for about $500. It doesn't seem that it should cost $500 to bury a 50 ft. electrical line. Depending on usage even preserved gas goes bad and has to be disposed of.
Warren
BillsBayou
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Re: Gasoline-Powereed Sandblasting Compressor Comparisons

Post by BillsBayou »

I thought that the SCFM rating was all that was needed to operate a sandblaster. If the sandblasting gun requires 10 SCFM and the compressor is putting out 12, shouldn't that be enough?
Second, the large capacity air tanks are needed to take the load off the compressor and not affect the volume of air flow.
If both of these are wrong, then it is the larger high pressure tank that is the real powerhouse behind a sustained air flow at higher volumes.

For reference, this video states "Remember, it's not the size of the tank that counts. It the volume of air that the compressor itself can output."

Going with the 230 volt compressor option involves complicated power supply options. The 10'x20' workshed only has a 120v-20amp supply. I don't think wiring the shed, 100-feet from the house circuit breaker box, with 240v is going to be cheap. So that's out.

This leaves two options:
1) Power the compressor from my 3300-watt generator. It has a 4-prong twist plug. The 60-gallon Husky generator needs a 3-prong supply. Adapters will be needed.
2) Run a 100' extension cord from the Husky to my garage where we have the dryer. The cost of 100' 240v extension cords are insanely expensive. I'd have to build my own. I can DIY new 120volt circuits in my home. I really don't want to touch a DIY 240v project.

Option 2 also includes a recommended inspection by a licensed electrical inspector. Option 1 would not... I think. So, Option 1 is my best choice.
The Hobbyist
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Re: Gasoline-Powereed Sandblasting Compressor Comparisons

Post by The Hobbyist »

Check out the Husky at HD that is also in the $500 range but uses 120vac. I've been using it for a couple years now and find nothing wanting. I picked it over the 240vac version because it is movable and (more importantly) it is quieter, so say the ratings.

I only do a moderate amount of sandblasting, no carving, etc.

Jim "The Hobbyist"
"With or without religion, good people can behave well and bad people can do evil; but for good people to do evil—that takes religion. " Steven Weinberg
Brad Walker
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Re: Gasoline-Powereed Sandblasting Compressor Comparisons

Post by Brad Walker »

BillsBayou wrote:I thought that the SCFM rating was all that was needed to operate a sandblaster. If the sandblasting gun requires 10 SCFM and the compressor is putting out 12, shouldn't that be enough?
No. It's not that simple. You also have to consider the psi you'll be blasting at and the size of the nozzle you'll be using. Then you have to size the compressor to also take into account that the nozzle gets bigger (i.e, requires more air) as it gets used.

For example, if you're using a 1/8" nozzle at 50 psi, you'll need a compressor rated at around 11 CFM. But once the nozzle wears to 3/16" the cfm required to maintain the same 50 psi balloons to 26.

The purpose of the tank (and the larger the better) is to store the extra air you'll need to continue operating and allow the compressor to rest (i.e., not run continuously) from time to time. Unless your compressor is designed to do that, it won't last that long.
BillsBayou
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Re: Gasoline-Powereed Sandblasting Compressor Comparisons

Post by BillsBayou »

The Hobbyist wrote:Check out the Husky at HD that is also in the $500 range but uses 120vac. I've been using it for a couple years now and find nothing wanting. I picked it over the 240vac version because it is movable and (more importantly) it is quieter, so say the ratings.

I only do a moderate amount of sandblasting, no carving, etc.

Jim "The Hobbyist"
What's the largest nozzle size you use?
Tony Smith
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Re: Gasoline-Powereed Sandblasting Compressor Comparisons

Post by Tony Smith »

For their size, gas powered compressors have way more flow than electric, but because they're portable, they have smaller tanks resulting in less reserve capacity. That said, SCFM at pressure is the indicator that you need to evaluate. Depending on your sandblasting setup, you may see some pressure fluctuation at the nozzle, but I think it's more likely that you'll see frequent cycling of the compressor engine to keep the tank pressure up. That would drive me (and my neighbors) crazy, but to each his own.

Tony
The tightrope between being strange and being creative is too narrow to walk without occasionally landing on both sides..." Scott Berkun
BillsBayou
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Re: Gasoline-Powereed Sandblasting Compressor Comparisons

Post by BillsBayou »

Tony Smith wrote:For their size, gas powered compressors have way more flow than electric, but because they're portable, they have smaller tanks resulting in less reserve capacity. That said, SCFM at pressure is the indicator that you need to evaluate. Depending on your sandblasting setup, you may see some pressure fluctuation at the nozzle, but I think it's more likely that you'll see frequent cycling of the compressor engine to keep the tank pressure up. That would drive me (and my neighbors) crazy, but to each his own.

Tony
This is exactly what I thought. The smaller your tanks, the more frequent the duty cycle. And, the more frequent the duty cycles, the shorter lifespan of the compressor.

What I'm thinking is happening with recommendations is that other people's sandblasters are drawing more air than the compressor can put out. If you pause during your work, you give the compressor time to catch up. If you pause enough and you're not drawing at a much higher rate than compressor capacity, you could get the impression that it is the larger tank that matters. Which it does, of course, but not for the reason you'd be thinking.

So, if I get the Makita wheelbarrow, I'll have to plan on getting a 60-gallon reserve tank at some point. This would increase my reserve to 70 gallons and the rest between duty cycles would be longer. Hmmmm... but then, while the Makita would have longer rests between duty cycles, it would now be filling seven times the amount, thus longer duty-cycles. Better keep an eye on the engine and compressor oil levels.

As for the noise level, yeah, running a gasoline compressor would be loud. What would really be annoying is the change in engine pitch and the engaged compressor for duty cycles. I can tune out a lawnmower, but if I hear someone running an engine back and forth between low and high loads, that'd piss me off.
Tony Smith
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Re: Gasoline-Powereed Sandblasting Compressor Comparisons

Post by Tony Smith »

Not exactly... by cycling more frequently, the gas-powered compressor will keep up with the demand, which is your main concern. This doesn't impact compressor life as much as you might think... going from empty to full pressure is way more stressful on a compressor than varying the pressure from 90 to 135 psi repeatedly. Also, the engine fluctuation probably isn't much more than your lawnmower going from thin grass to deep grass repeatedly.

Tony
The tightrope between being strange and being creative is too narrow to walk without occasionally landing on both sides..." Scott Berkun
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