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Glen
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1,504 Posts
Tex, you look at nozles at http://www.sand-blasters.net/

When you click more info under a selection it will tell you what cfms that nozle needs to run at its full ability. With a 185 you get the most out of a #5 (5/16) but you can run a larger one at less pressure like a #6 at 65 psi will give a larger hot spot but won't have the strength of the #5 at 90 psi. It depends what you need to blast. How many cfms do you have to work with?
 

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Todd
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848 Posts
media wont play a part in this..if you have the ability to go a little bigger in your air compressor i would ...if i had to do it all over.185 cfm is fine but if you start getting intoo bigger jobs you tend to feel a little slow rather than the guy GETING IT DONE...sorry again.
 

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Greg
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33 Posts
100 psi is considered 100% efficiency, so if you go up or down from there you will change the base line of the blast. In sand blasting terms it's desirable to blast between 100 - 125 psi or even higher if your equipment is designed for it.

Greg
 

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Glen
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1,504 Posts
All true but there are many reasons you will blast at much lower psi. Delicate items like an old wooden chest a fellow brought in to me. It had thin ornamental tin covering it loaded with old paint. I think I stayed around 60 psi with walnut. Might have blown right through if I started at 100 . You can always go up if you need to.

But for most regular blasting more is better.
 

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Greg
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33 Posts
Yes, I blast any where between 20 - 125 psi all depends on what you are blasting and level of profile you require. But using the same media on purely a performance base 60psi is 60% efficient 100psi is 100% efficient and 125psi is 125% and so on. this is as list on nozzle pressure blast charts.

Greg
 

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Registered
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20 Posts
I got this from the problast website
The following list compares the blast nozzle size to the compressor CFM requirements

Nozzle Tip Size
H.P.
Compressor CFM
# 3- 3/16"
10 H.P.
45 CFM
# 4- 1/4"
20 H.P.
80 CFM
# 5- 5/16"
30 H.P.
140 CFM
# 6- 3/8"
50 H.P.
200 CFM
# 7- 7/16"
60 H.P.
255 CFM
# 8- 1/2"
75 H.P.
350 CFM​
 

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Trial and Error Opperator
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2,018 Posts
If you have the resources to get a larger compressor, then go for it.
A 185 is a good starting, but as you get in to bigger jobs you start to feel inadequate, having larger cfm and psi behind you does make or break you on some jobs.
You can always turn down the psi, but when it's maxed - you cant turn it up! ;)
How many of you truly would like to go up to a larger compressor?
 

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Glen
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1,504 Posts
Just a note to those with smaller compressors. Don't let charts like that make you think you can't use a larger nozzle. I found that I can use a #7 with awsome results on my 185 cfm. It provides a much wider spray than the #5 that is the usual nozzle for 185 and is still more than enough power to blow the carp out of just about any normal project you have. I recomend a short ventury which will maximize the hotspot. I paid around $70. bucks for one. If I just went by the charts I would never have tried it. Reading is nice but experience is all that really counts.
 

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Trial and Error Opperator
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2,018 Posts
Glen, I have a bunch of nozzles I use. (had them from my last job)
and some new ones too.

#4, #6, #7, #8 I use all of these at different times depending on the job.
I like the 7 & 8 on cars.

I also took a cabnet blast tip (3/4 threed) and up sized it to fit the 1" hose.

I've used this for what I call Pencel blasting. gives a very small spot and maybe 50 psi. I use this for my nabor, lots of radiator brackes. Old one's $$$$ so I don't like to chance damage.
 

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Registered
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7 Posts
Texas,

We have a 210CFM sullivan Palatek Compressor 90hp diesel with 470hrs. Twin aftercoolers and Moisture seperator for sale. We would be willing to deal. If your interested give ua a call 701-223-1674.
 

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Registered
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1,255 Posts
Just remember, The pressure showing at the compressor is not the pressure in which you are blasting at, at the nozzle. If you are running a blast pot with 1 inch or 1 1/4 inch piping and your running 1 1/4 inch blast hose and your powering your blast pot with a 3/4 inch then your pressure drop will be increased even more. Low pressure blasting is good for delicate items but if your wanting to get the most of the CFM that you have availabile then your hoses need to be sized correctly. I would suggest to everyone to buy a Needle Pressure Gauge to see exactly what your pressures is at the nozzle. Like Glenn said, Experience means a lot. You cannot always go by a chart. The charts just get's you in the ballpark.
 

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Trial and Error Opperator
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2,018 Posts
I think I’m having a flash back of this post from before….
And before...
And before… :drink:

Just kidding’ these are questions that every one asks.
If you want to know exactly, do like Benny says and test the psi at the nozzle.
The more you play with your equipment (boy that doesn’t sound right) The more you will know what it does, and how it performs.
Practice, Practice, Practice!
 

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Mobile Sandblasting
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672 Posts
I put a pressure gauge/regulator on my pot. How close is that PSI reading to the PSI at the nozzle? I am running a #5 with my 185 and watched the pressure gauge at full blast and and it does not move, stayed the same. It will probably drop a little after tomorrow. I am adding my pneumatic vibrator to the set up but my research says its the most efficient vib unit out there with an internal exhaust port. Its hooked up to my 12v air valve so it comes on when the deadman is depressed.
 

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Trial and Error Opperator
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2,018 Posts
If I remember, some of those pneumatic vibrators can be loud.
you can cut the air flow to them (ball valve) to make them run fast or slow.

been a long time sence I used one, but they work good.
 

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Registered
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1,255 Posts
I put a pressure gauge/regulator on my pot. How close is that PSI reading to the PSI at the nozzle? I am running a #5 with my 185 and watched the pressure gauge at full blast and and it does not move, stayed the same. It will probably drop a little after tomorrow. I am adding my pneumatic vibrator to the set up but my research says its the most efficient vib unit out there with an internal exhaust port. Its hooked up to my 12v air valve so it comes on when the deadman is depressed.

You will have a pretty good pressure drop at the nozzle. It would amaze you just how much it does drop. Running more air driven equipment with a 185 and you will have even a greater pressure drop.
 

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Trial and Error Opperator
Joined
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2,018 Posts
Benny you might know..

Isn't there a psi drop for every 10 feet of hose?

and can they figure (roughly) the drop at the nozzle.

I want to say something like 2-3 psi for every 10 feet of hose?

:scooter:

Thanks Benny!
 
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