building crevice blaster? Help please.

[Sticks]

Hello smart bench, I'm trying to build a crevice blaster for 4" dredge. I picked up parts today and only saved $25 vs buying one from keene, (typical of my builds) cost twice as much, are far heavier, and work half as well. lol. I guess my question is on the nipple for the blaster, I plan on cutting it at a 45 and welding to 2" nipple. does the smaller nipple need to extend into the 2" nipple at all or should it be flush inside? Is 45 degrees the right angle? Thank you smart people. I appreciate you. Rob

 

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[Hoser John]

On you pump,on the pressure side, there should be a hose adaptor threaded like a garden hose if keene,proline,nugget,dahlke,precision and others. What kind of pump ya using?. A simple T fitting on a trash/clearwater pump works just fine also with a simple screw in adaptor and a hose bib. No cutting no nuttn' just teflon tape ,screw on and good to go. John

 

[Sticks]

thanks for your reply, it's a p180 keene, and yes there is a garden hose port. Thought that more than one of your threads said gh off side of pump was insufficient for blasting. I have used that port on previous dredges with some success definitely better than nothing. Thought all you pros liked a bigger blaster. I know that 1" that I plan on adding will rob precious flow to 3 stage, but shouldn't be any different than capping nozzle with a flat rock when rolling boulders. I don't plan on opening all the way all the time, but can use up to 1" of full pressure off pump. I will go ahead with build and try both will post results when I get back latter this summer, Thanks again John all the best to ya. Rob

 

[Sticks]

finished build thanks, I pressure tested and no leaks. Not sure how long that silicone will hold it together but will see, lol

 

[Hoser John]

BLOW THEIR MINDS AND GET'R ALL the hose bibs work fine if you go 5/8" non kink hose with a valve and lawn sweeper nozzle. Either way your a gonna get it all now and soooooooooooooooooo much faster-John

 

[kazcoro]

Looks pretty good. Gonna get a lot more flow than trying to use the prime port that is for sure.

 

[Armchair prospector]

20 ft' of garden hose the same distance as the suction hose. The blaster I use(d) on mine was with a 3/4" PVC threaded shutoff then reduced down to a 6"x 1/4" galvanized nipple. Worked great. Didn't have to change or modify the pump at all. No welding at all. Being a plumber helps.

 

[Sticks]

Looks pretty good. Gonna get a lot more flow than trying to use the prime port that is for sure.

Great! my last dredge had a p250 keene on it and I used GH or prime port, it worked ok but would like to have more for the clay hardpack I'm in. I should have plenty now and likely wont have to open valve all the way. Just worried about the three stage as
it is new to me, I'm clueless on how to run them, super fine gold here, I mean finer than beach gold and lots of it. I have seen ore from this district that was well over 5 opt and it would cover your hand in powder gold so fine you couldn't see it unless you were in sunlight. I know I don't have a prayer of getting to much of that but I can try. Mostly 50mesh that I get with highbanker

 

[omnicron]

Sounds like you should be running gold hog mat...I'm finding this stuff catches below -200 mesh. You'll like you blaster setup.

 

[GrizzlyGremlin]

I had to waste $40 today on a quick blaster. Its just 3/4" down to 1/2" its simple but its getting a test run tomorrow. I also have a question. How many psi does a 4" dredges water pump output? I want to make a 5' long 3/8" dia attachment for thin cracks and delicate crack work. Will just shotty 50 psi vinal work for a short section? Its cheap stuff

 

[Timberdoodle]

generally a dredge will run in the range of 30-40psi so no problem with the hose. You may find that what you have already built will do everything you need. Restricting down to 3/8 for 5 feet may kill the pressure and not work as well. Simply adding a 1 ft 3/8 line onto your 1/2 may work if you really need the size restriction.

 

[omnicron]

That will work just fine. Your pump wont put out enough pressure to burst anything. If everything is working right, you may see 30ish psi.
If you would of got a galvanized bell reducer you could of changed out the nipple for longer or shorter ones plus galvanized is 100 times more durable then brass.

 

[Reed Lukens]

1¼" hardline fire hose works great Did you say silicone? I usually put the Y down at the jet but I run a 9hp 500gpm pump on a 4" dredge wide open. This dredge is a little bigger

 

[Sticks]

1¼" hardline fire hose works great Did you say silicone? I usually put the Y down at the jet but I run a 9hp 500gpm pump on a 4" dredge wide open. This dredge is a little bigger

View attachment 1007155

Silicone was my poor attempt at being funny, sorry no it is welded, well kinda was a windy day hard to keep envelope on weld. Glad to see that you have a big blaster I was starting to think that my 1" was overkill.

 

[Sticks]

Gold Hog mat

Sounds like you should be running gold hog mat...I'm finding this stuff catches below -200 mesh. You'll like you blaster setup.

Thanks Omnicron, I would love to run gold hog mat in my 3 stage dredge. I am looking for any information on that set up. I have tried to scour the net for info. if you have had any success particularly with a 3 stage please let me know. My 3 stage is stock. I don't trust it.
The gold in my district is super fine. Which mat are you using? I do value your feedback... Rob

 

[minerrick]

Hello smart bench, I'm trying to build a crevice blaster for 4" dredge. I picked up parts today and only saved $25 vs buying one from keene, (typical of my builds) cost twice as much, are far heavier, and work half as well. lol. I guess my question is on the nipple for the blaster, I plan on cutting it at a 45 and welding to 2" nipple. does the smaller nipple need to extend into the 2" nipple at all or should it be flush inside? Is 45 degrees the right angle? Thank you smart people. I appreciate you. Rob

Depending upon where I am working, instead of a normal pressure hose for a blaster (I still use one for softening up the looser pack), I went out and found a 2500 psi pressure washer at a garage sale. I modified the platform so it sits better on uneven ground. Depending upon how hard the bedrock is, it also does a pretty good job of busting up bedrock too. Swinging a hammer is pretty hard under water and a 2500 psi stream of water at 1/8" diameter does a nice job of breaking up lots of bedrock. The nice thing about under water is the stuff you are blowing out doesn't go far. For on the sides of the river outside of the water channel, I was thinking of going to Harbor Freight and getting their corded demolition hammer. I bet that would be a good bedrock breaker too. Why screw around.

 

[Armchair prospector]

If you need to test just go to you hose bib on your house. Most homes have 60 to 80 psi if on city water. Will differ on a well. Start with 3/4" and reduce down until you get what you desire. With a ball valve you can control how much you need to blast. Having the nozzle right there will suck it all in.

 

[russau]

I use a Dave Frank jet device (PVC) called the Vortexrex and Dave installed several ports on this venture for 3/4 and or a 1 1/4 inch hose. it takes its water pressure for the blaster right off the water chamber that is feed from the 2 inch hipressure line from the pump! never needed to use the 1 1/4 inch line because I had PLENTY of pressure for the blaster.and Oh yea, ive used this PVC jet for atleast 10 years and it has never given me any problems!

 

[Sticks]

update, that blaster worked awesome! I will never dredge without one again thanks everyone for your input. Shredded the bedrock in some cases made winching out broken bedrock easier too. Sticks