what did I do wrong - 2 smaller air compressors into 1 for blasting

[twentythreemx]

Hello - I bought a HF blast cabinet without doing much research and didn't realize the importance of CFM with air tools until now, whoops.

Keep in mind it's a new unit, maybe something withe gun is bad? But it wont siphon up any media. I'm convinced it's my compressor.. Its only a 35 galllon and is like 6.4cfm at 90 psi and the cabinet says it requires 9.8 cfm at 90psi.

So I thought maybe I can hook up my smaller 13 gallon compressor in parallel with it. Reading a few threads about it, seems common, and if I add CFM from each of them, I'd be right where I need to be.

Well I tried, and failed, and it's still barley trying to **** anything up the media hose. I can get a little to come out sometimes if I press the tip up against an object..

I saw a lot of different methods of hooking up the 2, and have no idea what's right or wrong. So here is what I did do, can someone plese tell me where I maybe went wrong?


Compressor 1, 35 gallon larger unit: ran normal output line to a T. The T goes into a water separator/filter, the other side of the T goes into compressor 2, the smaller one connected to normal output.

regulators turned fully at 100% on both compressors. The output of the water filter then goes to the blast cabinet, where I hooked up a regulator mounted into the input of the cabinet. That way the air isn't regulated at either compressor, and is done so evenly at the cabinet itself.

Also I hooked both up to the T and did the T on the other side of the filter, so that both units are filtered air coming through.

It doesn't seem to work any better (maybe like, a teeny tiny bit) than when running off just the 1 larger compressor. I did have to use a lot of hose to do this, and all I had was 50 ft hoses, so I have a ton of hose, and some is 1/2 some is 3/8, and a lot of quick connects.

Could the 3/8 hose and quick connects be killing the volume/pressure? Or did I maybe just get a broken gun?

Or do I bite the bullet and run the 220 and get a new compressor. (I know thats probably prefered, but for a new "hobby" that really wasnt in the budget)

Any thoughts on my config? I saw some ppl say touse check valves, other ppl say it's not needed. One thing I read said to put the line coming out of the relief valve, not the regulated side... not sure what difference that would make if I open it up all the way... doesn't seem like it should be rocket science but clearly I ****.

Any help is appreciated thank you!

 

[yhprum]

Can you feel any suction on the media feed line? maybe you could connect a vacuum gauge to see what you are getting. Maybe you have a buddy with a bigger compressor you could try it on?

 

[matt_i]

Eliminate quick connects if possible, they are very restrictive.

Its extremely important that the air be moisture-free or it will clog/jam the nozzle.

 

[Monza Harry]

You didn't mention the grit size, too fine can pack in the hose/nozzle, that requires an air bleed near the bottom of the suction hose. Also to coarse of grit may not even get in/through the nozzle. The two compressor set up can work without any fancy set-ups but you will likely end up using just the one until your pressure is actually to low to get your gun functioning properly. If the one is running constantly and the other only comes on occasionally you will need to get fancy, probably cheaper/better, then to buy/sell/trade/barter a bigger compressor. Harry

 

[nadogail]

IMHO, using multiple compressors to feed a common receiver makes sense.

I sometimes do it when I need higher volume than my usual compressor can produce.

 

[will335i]

What is the combined CFM of both compressors? If it is right at the required 9.8 then you don't have enough because even with ideal connections you are going to have some loss along with some loss going through the filter. What is the CFM rating on your filters? It is possible they are too restrictive and cutting your flow.

 

[twentythreemx]

I didn't see a CFM rating on the filters but PSI was way higher than what I required.. I'll have to double check again.

Combined rating for cfm between the 2 compressors is right where I need to be (I think it was like 9.9 off the top of my head?)

Tried 2 different medias, one medium one fine... same results on both.

very little suction at the end of the metal rod going into the media.. didn't try to feel suction at the gun w/ the hose removed but I made sure theres nothing in the hose or rod thats blocking it.. will try that for the heck of it. i should pulll that out and make sure I dont have a leak in that hose somewhere or something..

Got a new gun on order too just in case.

 

[csp]

The HF suction tube is a joke. There are several upgrades you can either do yourself to make it more efficient or TP Tools sells a replacement tube. See youtube for videos on DIY fixes.

I doubt if it's the compressor(s) that are the problem.

 

[Leaflessshadetree]

If your hoses/fittings/filters etc are capable of passing the required CFM it should work at least for a short burst regardless of CFM from the compressors.
I can blast for 20-30 seconds from my 33 gallon tank. Then wait for the tank to refill (I'd estimate this worn out oil less probably putting out about 3 CFM if that).

 

[welder4956]

I had the same issue with my HF blast cabinet. The gun kept clogging with sand and it had poor suction. I installed the TP Tools pickup tool and gun and have had zero issues since.

 

[twentythreemx]

im convinced its my gun or pickup tube, i get like no suction.. i got a new gun that will be here tomorrow. i tried loosening the cap and making sure the tip was loose and free and i got a little out of it for a few seconds.

can anyone confirm how the tube from HF should be hooked up? its a smaller tube inside a larger tube.. with the smaller tube being longer on one side. someone online said they reversed theirs and then drilled a hole in it but im nervous with my low cfm that hole might be a bad idea.?

 

[Jswain]

Turn your air pressure down to 40-60psi and if you have the smaller of the ceramic tips in(4-5mm) switch to the larger size (6-7mm).
Go ahead and modify your pickup tube as it will help your problem as well. Cap off the end of the air siphon tube on the bottom(the one your hose is NOT hooked up to) then drill a 5/16 hole through 3 walls drilling from the air siphon side, then cap the outter wall so your hole just connects the inner two walls. Smear some epoxy along the sides where you just drilled as well to seal them off. Then about and inch up from the top of your air siphon tube, drill a 1/8 hole in the media pickup tube(the one your hose is connected to)

All of this will meter in more air to the media providing better media flow as you won't **** in big chunks and clog instantly. Reducing your pressure further helps that so start there because it's free and easy. And pickup the 4,5,6,7mm tips if you didnt get a pack with the cabinet and experiment which one works best but I'd imagine 6mm will provide the most suction

Just seen you have the one tube inside the other, probably worth switching to the two tubes beside one another you can make or buy, start with the pressure and tips first then if not modify or change pickup tubes

 

[BillK]

One more thing to mention. What media are you using and where are you buying it ? This is another case of "you get what you pay for" I ran low on glass beads at my shop one time and went and got a bucket at Tractor Supply to tide me over. That stuff was absolutely no good. Did not work worth a darn and kept clogging.

Sand is the same way. There is a big difference in sand that is made for blasting and what you can buy at Home Depot.

 

[twentythreemx]

One more thing to mention. What media are you using and where are you buying it ? This is another case of "you get what you pay for" I ran low on glass beads at my shop one time and went and got a bucket at Tractor Supply to tide me over. That stuff was absolutely no good. Did not work worth a darn and kept clogging.

Sand is the same way. There is a big difference in sand that is made for blasting and what you can buy at Home Depot.

Was using the stuff from TSC.. grabbed a bag of fine and the medium..

Anyhow, I'm up and running. I don't know what the magic trick was, I didn't change anything in my setup, but I pulled the gun out and blew it out from every angle.. and same w/ the pickup tube. there's not much gap for air betweein the inner and outer tube.. im thinking something was real stuck in there...idk...

Got it working w/ the stock gun, largest tip seems to be best, better than smaller which I thought is backwards, so I was trying smaller before..

replaced w/ cheap amazon gun and that gun works a bit better than the HF gun.. (picked the one I found w/ the lowest posted CFM requirements)

https://www.amazon.com/gp/product/B07N2JZL81/?tag=atomicindus08-20

I think if I replace my pickup tube w/ the 2 rod style.. I'll be in even better shape, so I think that's next on the list.

Thanks for everyones input! I think I was trying to overcomplicate it. Probably was just the stupid pickup tube or something jammed in the gun the whole damn time!!!