Grit Hose Clogging

[Pollys13]

The grit hose has a 10mm bore, 2.5mm nozzle bore, hose is about 6 feet long with a gentle bend and going up into cabinet. Using 120 mesh S/C grit Have water trap on main regulator going into system. 90L Compressor is set to 90 PSI, the pot 40PSI, 65PSI. The grit seems bone dry to me but is, seems..... deceptive? If only a minute of moisture get into grit can that cause it to clog?
I checked the system and it was the grit hose blocked, not pot ball valve or anything else.
Any advice appreciated,
Cheers.

 

[brightspark]

either dampness causing the blockage or 2 much media entering the blast hose and clogging at the jet . if it runs for a while ok then clogs possibly water. if it blocks virtualy instantly its 2 much media or the media is 2 large for the jet to handle

 

[Pollys13]

OK I'll double check on how it runs. I've got a humidity meter I used for something else, put next to compressor couple of hours ago, says 72%. Also have a Which Magazine best buy dehumidifier, again bought for something else. Think when that runs, gives an indication of moisture in the air.
As I say, even though the grit seems perfectly dry and runs like sand through my fingers, could it...... still have enough moisture in it, causing to clog?

" 2 much media entering the blast hose and clogging at the jet . if it runs for a while ok then clogs possibly water. if it blocks virtualy instantly its 2 much media. " Will check these out as a process of elimination. I don't really want to spend several 100 on an Abac compressed air refrigerated dryer.
Cheers.

​

 

[brightspark]

no need for a refrigerated dryer i havent got one and dont need one .i just use a secondary tank on the end of my airline then in to the shotblasting pot fitted with the water seperator. the tank dehumidifys the air and water drops to the bottom so the water seperator hardly has to only seperate a bit of moisture

 

[Matchless]

grit could also be too er gritty, Mine came with crushed glass, bits were too large and too rough, clogged at the slightest bend etc. cannot type any more, feels like I have broken my right arm..... pulled my bicep last night, cannot even pull my trousers up today, waiting for my wife to come home and oblige.

 

[Pollys13]

no need for a refrigerated dryer i havent got one and dont need one .i just use a secondary tank on the end of my airline then in to the shotblasting pot fitted with the water seperator. the tank dehumidifys the air and water drops to the bottom so the water seperator hardly has to only seperate a bit of moisture

What would be the best way for me to unblock a 10mm bore grit hose?
Cheers.

 

[Matchless]

blow backwards

 

[brightspark]

What would be the best way for me to unblock a 10mm bore grit hose?
Cheers.

depressurize it take the jet of the end and re pressurise it with the grit valve turned off . it will all just blow out

 

[Pollys13]

depressurize it take the jet of the end and re pressurise it with the grit valve turned off . it will all just blow out

If the grit valve is turned off I don't see how it will get blown out? Do you mean empty the pot of air, take tip off end of hose, re pressurise it with the grit valve turned off....... then open valve to blow through hose to clear it?

 

[fizzy]

I always use a sieve before filling my blaster - even good quality grit often has a few odd lumps in there.

 

[brightspark]

turning the grit valve off at bottom of the pot stops the grit flow down in to the tee piece but turn the air supply on and the pot will pressurize and air will also go down from air feed to the blast hose and will blow it clear

 

[Pollys13]

I always use a sieve before filling my blaster - even good quality grit often has a few odd lumps in there.

Thanks for the tip.

 

[Pollys13]

turning the grit valve off at bottom of the pot stops the grit flow down in to the tee piece but turn the air supply on and the pot will pressurize and air will also go down from air feed to the blast hose and will blow it clear

OK cheers.