# I need some technical help.



## Dawna_Radio (Aug 11, 2021)

I need help selecting and putting together an air compressor and its accessories. You can see in the image attached how and what parts need to be connected. I feel overwhelmed by trying to select accessories such as an air hose, filter, regulator, coupler and plug, etc.

The compressor is to be attached to a Central Pneumatic 20 lb. abrasive blaster 68994. The owner's manual shows a diagram of the connections for attaching the accessories to the abrasive blaster on page 12, but no detailed information about inner and outer diameters of the parts. Manual: https://manuals.harborfreight.com/manuals/68000-68999/68994.pdf Warning: .pdf
You can see the blaster on pages 9 and 10 in the manual.








Compressor-With-Accessories-I-need


Image Compressor-With-Accessories-I-need hosted in ImgBB




ibb.co





Abrasive Outlet Pipe female end 9/16 inch interior diameter"
Abrasive Outlet Pipe male 5/32" inner diameter (Because of the way the part is constructed, it's not possible to measure the outer diameter."

Harbor Freight sells Central Pneumatic tools, but when I emailed Tech Support, they never replied. The owner's manual lists Central Pneumatic's tech support number, but when I called them they never replied.

Blaster Specifications: Specifications

Are these connection parts standard? Can anyone guide me so I can attach a compressor? I've been looking at compressors. and I'm wondering if this one would be suitable: https://www.amazon.com/gp/product/B00UHNM1R0/ref=ox_sc_act_title_2?smid=ATVPDKIKX0DER&psc=1

I'm sorry for the amount of text, but I wanted to explain clearly. Any help from anyone who can advise me will be very much appreciated. I had trouble inserting images, so I hope the links work.


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## stevon (Mar 5, 2019)

Dawna_Radio,

You need a 10 CFM at least (240 volt 5HP+) and a constant run model at that: 








Rolair 5HP Single Phase Constant Run Electric Air Compressor w/30 Gallon Air Tank H5130K30HB - Spray Foam Systems


Rolair 5HP Single Phase Constant Run Electric Air Compressor w/30 Gallon Air Tank H5130K30HB



www.sprayfoamsys.com




to get any serious work done. Compressors are very inefficient a 5 HP compressor can only run a 1/2 air motor tool constantly. That pancake compressor is a joke for this application. a 10 HP or more commercial compressor would be best. There also is the issue of sand media. Don't use play sand from home depot, it will clog instantly and constantly. 6 CFM to 25 CFM air consumption is listed but at the minimum 6 CFM (240 volt 3HP compressor) only a pencil size blasting area will be coming out of the nozzle. 1/2 air line and 3/8 fittings would handle the high CFM requirements, the problem for you is the compressor needed to do the job. What do you plan to sand blast and how big is the project? You can get a commercial outfit to sand blast your small items for less money, time and expense, I use a place that does powder coating and sand blasting in San Diego
RW Little, they are very reasonable and you get a superior finished product! 

Stephen


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## Dawna_Radio (Aug 11, 2021)

stevon said:


> Dawna_Radio,
> 
> You need a 10 CFM at least (240 volt 5HP+) and a constant run model at that:
> 
> ...


Thank you stevon for your reply and the information. I actually had a tech support representative at Harbor Freight who was patient and willing to look at the Owner's Manual. She said all the fittings/joinings would be 1/4 inch, but you suggest 1/2 inch air lines and 3/8 inch fittings. I think you seem more learned about this than Harbor Freight Tech Support, though I appreciate that she tried. I plan to use bicarbonate of soda as the abrasive medium, and I know the baking soda in the supermarket can't be used.

The piece I need to sandblast is a piece of sculpture about 10 inch high. It has some type of steel alloy as a center column punctured in a hopefully nice design, but through repeated exposure to water, the inside of it is getting rusty. On the central column are many red brass wires about 3/32 of an inch (1.75 mm) soldered to it. Off of the wires are more branches with elements looking like a puff of pine needles. Unfortunately, I bought Flits Tarnish remove, and after I sprayed the Flits onto the piece I was left with a layer of green copper oxide on all the brass. It's out of the question to try and use wire bristles to remove the copper oxide because the wires are so twisted and intertwined. The pine needle puffs are quite small and impossible to get wire bristles into.

I took the piece to a local abrasive blasting place, but the guy there said he wouldn't do it because it might be to fragile to survive the process. I'm optimistic still, but I thought why should I pay someone to clean it when I can buy the equipment. I've used an abrasive blasting cabinet in the past, and there's a good possibility I might make more sculptures that could need cleaning, or to create esthetic effects- glass, wood, metal, stone, etc.

Maybe tomorrow during the day I'll try to add a photo to this post. My phone camera isn't very good.


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## stevon (Mar 5, 2019)

Dawna_Radio, 

You do have a special case and most commercial places don't use bicarbonate of soda because they are doing a different process. Most places have a air filtered room, they put all the parts to be sand blasted it, blast away at the heavy stuff and then move the partially blasted stuff to the front and go over them briefly. Rust and coating removal is the main goal. Not a delicate process in any way, more of a brutal technique. 1/4 inch fittings could work for you and they are cheaper than 3/8" bore fittings. For your application, for an air source nothing less than a minimum 240 volt 17 amp/3 HP compressor and then run it for no more than an hour. Longer run time and the motor's thermal overload will trip and shut the compressor down before it burns up. You can get constant run 3 HP compressors but they are pricey. Don't be fooled by *marketing advertisement BS * "Develops 3HP and runs on 120 volt" advertised on some model compressors. Physics doesn't lie, to develop and produce 3HP actual mechanical output, a modern efficient motor must use at least 240 volt @ 15amps FLA.
Are you buying a compressor? do you have access to 240 volts? Will you use it for other projects? Do you have a budget in mind?

Stephen


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## Dawna_Radio (Aug 11, 2021)

stevon said:


> Dawna_Radio,
> 
> You do have a special case and most commercial places don't use bicarbonate of soda because they are doing a different process. Most places have a air filtered room, they put all the parts to be sand blasted it, blast away at the heavy stuff and then move the partially blasted stuff to the front and go over them briefly. Rust and coating removal is the main goal. Not a delicate process in any way, more of a brutal technique. 1/4 inch fittings could work for you and they are cheaper than 3/8" bore fittings. For your application, for an air source nothing less than a minimum 240 volt 17 amp/3 HP compressor and then run it for no more than an hour. Longer run time and the motor's thermal overload will trip and shut the compressor down before it burns up. You can get constant run 3 HP compressors but they are pricey. Don't be fooled by *marketing advertisement BS * "Develops 3HP and runs on 120 volt" advertised on some model compressors. Physics doesn't lie, to develop and produce 3HP actual mechanical output, a modern efficient motor must use at least 240 volt @ 15amps FLA.
> Are you buying a compressor? do you have access to 240 volts? Will you use it for other projects? Do you have a budget in mind?
> ...


Yes, I'll buy a compressor. I just looked in the breaker box and it say 120/240 AC. I'll use your specifications to search for a compressor. My budget is extremely tight, but I'm willing to spend as much as possible to buy decent quality equipment. The only other times I'd use it would be making art. It may seem extravagant to buy an expensive compressor, but I put many hours into the piece and I think it would be very nice with the rust removed and the brass clean and shiny. I plan to coat it with clear gloss plastic spray.

I tried to get a good photo of the piece, but this is the best my phone camera can do:
Sculpture


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## stevon (Mar 5, 2019)

Dawna_Radio, 

I can see why a sand blasting outfit would shy away from your delicate project. A "homeowner grade" compressor could work for you, I have one that's over 20 years old and still working fine











https://www.lowes.com/pd/Kobalt-60-Gallon-Two-Stage-Electric-Vertical-Air-Compressor/1000542193



or 



https://www.northerntool.com/shop/tools/product_200756209_200756209



is all you would need

Stephen


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## Dawna_Radio (Aug 11, 2021)

stevon said:


> Dawna_Radio,
> 
> I can see why a sand blasting outfit would shy away from your delicate project. A "homeowner grade" compressor could work for you, I have one that's over 20 years old and still working fine
> View attachment 9980
> ...


Thanks for the links, but those compressors are too high priced for my budget. I've been using the search terms "140 volt A/C 17 Amp 3 HP air compressor" using various search engines, and on eBay and Amazon also. They give results that have nothing to do with what I need. I'll keep trying. Maybe I can try Craigslist and advertise for a used one.


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## stevon (Mar 5, 2019)

Dawna_Radio,

The 3 HP Kobolt for $500 is a good value and the one I would buy. When you say:
"140 volt A/C 17 Amp 3 HP air compressor" I said "240 volt @ 15amp" or more. Any smaller would be a toy and would burn up or overheat and shut down after 20 minutes or less.

Stephen



Dawna_Radio said:


> Thanks for the links, but those compressors are too high priced for my budget. I've been using the search terms "140 volt A/C 17 Amp 3 HP air compressor" using various search engines, and on eBay and Amazon also. They give results that have nothing to do with what I need. I'll keep trying. Maybe I can try Craigslist and advertise for a used one.


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