Super aggressive sandblasting setup - 1/2 inch hose too big? + 80 gal setup

[CamaroMan]

Hi all - so i recently decided im going to sandblast my own heads at the shop for crack checking etc. I have a 230v 80gal 6.5hp setup and just rebuilt the powerhead.

Was going to go 3/8 over 1/4 but found a 50ft roll of 1/2" hose yesterday so snagged it with some 1/2" couplings. Im wondering if the 1/2 hose would be too much? Could/Would it run the comrpessor out too fast?

Im doing the media metering valve out of pipe fittings and will most likely have a 1/2 valve up at the top to control air flow in case its too much. Ill prob run to a high flow 1/4 or 3/8 inside the cab with a swivel bit at the gun base but wanted 1/2 between compressor and cab.

Is this overkill and does it make sense to have an adjustable air valve at the cab for light/med/heavy duty blasting?

Will be using black oxide media and bought this to fit cylinder heads

Thanks

 

[CamaroMan]

Also considering stainless shot that I can clean up - any idea what size would be a good all round?

Found this chart online -

 

[PCustoms]

Your air hose isn't going to run the compressor out too fast....

The air consumption is determined by what you have at the end. Grinder, impact, nozzle etc.

You have to have a hose big enough to transport the required CFM, bigger isn't detrimental (it's slightly beneficial) in a fixed application.

 

[finn]

Orific controls the discharge rate. The large diameter hose will be stiff and unwieldy compared to a smaller diameter hose, though. Personally, I would look for a smaller hose.

 

[BillK]

I use glass bead and it is still a pain to get totally out. I am thinking of going to soda blasting instead. My compressor is 7 1/5 hp and it works just fine. I have a 3/8 hose going from the wall to the blast cabinet. Anything bigger is a waste. The nozzle opening is only about 5/16" if that.

 

[Jswain]

Orific controls the discharge rate. The large diameter hose will be stiff and unwieldy compared to a smaller diameter hose, though. Personally, I would look for a smaller hose.

Smaller then 1/2 hose from compressor to sandblast cabinet? No thanks

OP are you using a foot pedal or just a trigger gun? No need to a valve to control the air flow, the more air flow the better sandblasting will be.

A regulator, right on the cabinet would be a wise choice tho for adjusting pressure. And better to adjust it right at the cabinet and leaving your line pressure high to reduce pressure drop.

 

[PCustoms]

Orific controls the discharge rate. The large diameter hose will be stiff and unwieldy compared to a smaller diameter hose, though. Personally, I would look for a smaller hose.

It's fixed between the compressor and cabinet, who cares?

 

[Jswain]

I use glass bead and it is still a pain to get totally out. I am thinking of going to soda blasting instead. My compressor is 7 1/5 hp and it works just fine. I have a 3/8 hose going from the wall to the blast cabinet. Anything bigger is a waste. The nozzle opening is only about 5/16" if that.

Long smaller ID hoses will negatively impact your flow more then 1 single nozzle restriction.

I used to think my 3hp compressor kept up pretty good, until I eliminated the 3/8" hose reel and stepped up everything to 1/2". It was then I realized a bigger compressor would make things much nicer. Once I got the bigger compressor then I realized how inefficient the previous setup was, and things that I thought "damn this paint must be tough" was just a ****** setup.

Don't believe me hook nothing but a 1/4" male fitting to your disconnect at the end of a 3/8"1 hose reel and time how long it takes to drain your tank open ended.

Now hook the same fitting directly to the tank or using a 1/2" hose.

Doesn't make a difference on a tool that doesn't require it, say a 1/4" air ratchet. But when you supply the same hose to a blast cabinet or pressure pot it will say thank you.

If you can eliminate all the quick disconnects etc even better, hardline all the way to the cabinet with just a short lead in hose better yet.

 

[BillK]

Smaller then 1/2 hose from compressor to sandblast cabinet? No thanks

Why ??? My cabinet has a gauge on it. 90% of the time I keep it at about 50 psi. It never drops from that even if i am running it for 20 minutes straight. My entire shop is plumbed with 3/4" copper. There is about a 6 ft 3/8" hose from the wall to the filter separator on the blast cabinet. Has been that way for over 20 years. Never been a problem and I typically blast a few aluminum cylinder heads every single day.

I will say that my compressor runs at 150psi but it really should not matter.

If you are not loosing pressure then why do you need a larger feed ??? If the nozzle is only 5/16" then what good is a larger feed going to do ??

 

[Metal-Marc]

You have to have a hose big enough to transport the required CFM, bigger isn't detrimental (it's slightly beneficial) in a fixed application.

This.

If you are not loosing pressure then why do you need a larger feed ???

Overkill is fun Bill, just like punctuation, moar is better.

 

[Jswain]

Why ??? My cabinet has a gauge on it. 90% of the time I keep it at about 50 psi. It never drops from that even if i am running it for 20 minutes straight. My entire shop is plumbed with 3/4" copper. There is about a 6 ft 3/8" hose from the wall to the filter separator on the blast cabinet. Has been that way for over 20 years. Never been a problem and I typically blast a few aluminum cylinder heads every single day.

I will say that my compressor runs at 150psi but it really should not matter.

If you are not loosing pressure then why do you need a larger feed ??? If the nozzle is only 5/16" then what good is a larger feed going to do ??

6ft of 3/8" hose isn't as big of a deal as 50ft.

Your compressor @ 150psi is a big help though too. People with a single stage compressor really will benefit from a larger hose size.(In long run scenarios or using hose reels)

You blasting @50psi also helps. There's a 100psi differential between your cutout and your blasting pressure.

This is why people struggle with air tools. Set the regulator on the compressor for 90psi then run 50ft 3/8" or 1/4" air hose and some restrictive fittings and they cant understand why the tool lacks power....pressure drop

This is also why people with very long runs between the compressor and high volume tool install a little buffer tank at the tool.

 

[Metal-Marc]

install a little buffer tank at the tool.

This.

I have a 5 gal tank just before my main 1/2" hose reel. I also have a 20 gal tank on wheels for when I use a much longer run to do stuff in the yard.

 

[cnc-me]

1/2" hose for me, but I'm running at least two compressors rated at 25 HP total.
With another 5 HP compressor in reserve, if needed, depends on how wore out the nozzle is.

 

[ycgoat]

I have found that tubing and hose size is less of a concern than moisture control.

 

[mm08822]

Throw a ball valve inline to the cabinet supply. Throttle it if needed - if no value, run it wide open.
You really want to meter the media usage and the impact energy so you don't destroy your parts or blow through media too fast.

Fly swatters due less damage than the shot gun approach.

 

[mm08822]

I have found that tubing and hose size is less of a concern than moisture control.

I gave up on sandlasting years ago b/c of moisture causing blockage. I might pursue now that I finally own a refrigerant dryer.

 

[CamaroMan]

thanks for the great responses guys- yes will have a ball valve at the tank in case i need to slow it down. I dont have electricity enough so have to run my diesel gen for the large compressor.

I will be modding the compressor to run the hot air thru a water cooling system before it enters the tank (guy on youtube did this with great results). Will stick with 1/2 to cab then and adjust as needed.

 

[B88i45]

I'd be less worried about oversizing the air line, I can't imagine having too much air for blasting. Now oversizing the metering valve is something I've questioned as I price out the price difference between 1 1/4" vs 3/4" black pipe fittings.

 

[CamaroMan]

agreed was wondering about that- few pieces of pipe are cheap and there is a slight taper in the reduction, also not sure how important a factor the venturi plays in the metering valve. production ones have a long taper, diy ones use the short taper in the adapter 1-1/4 down to 3/4 or whatever size