DIY crevasse cleaner, gravel pump, chupadora

[BillA]

This thread is about building a suction pump for crevasse cleaning, and then rebuilding it, and then yet again, and . . . . where does it stop?
It is a DIY thread including particularly design or fabrication novelties, hands-on experience works.
(mods, if in wrong place - move 'er)
Many names for these, manual gravel pump is descriptive, gold sucker is common, and my favorite is chupadora (sucker in Spanish).
An old-timer seeing one called it a chupadora, used for removing gold from full riffles without shutting down the sluice.

As I am in a remote, but gold-bearing, area my only option is to build from that which is at hand; PVC DWV here we come.
I took a gander at the 'net to find out what everyone else knew/offered and of course made a list:
- ovaled end of suction tube with pin (maximize size while limiting blockage)
- changeable suction nozzle diameters/lengths ?
- retention resiviour for the work product that is easily emptied
so I made one (shown is the last of the straight pumps, I use clear tubing when I wish to see what's happening)



A bit of use and it was very clear that the pump body should be offset from the suction head for comfort.
At the same time that a 45 ell was added, following the maxim that more is better, the 1 1/2" suction tube was exchanged for 2".



And in 2" exploring resiviour configurations:



So what was learned from these prototypes ?
1) the suction tube diameter and length is limited by the pump displacement (no free lunch)
2) having to discharge the sucked-up water through the same tube is disruptive as hell. No stroke is truly completed, good stuff dribbles out the tube end; terrible efficiency
3) top of resiviour should be below bottom of branch connection and resiviour needs to be translucent

Obviously a second discharge/jet tube needs to be added and the flow controlled such that the suction tube sucks and the pressure tube jets. Enter check valves, one suction and one pressure. Note that the suction tube ck valve must freely pass everything one thinks to retain, while the pressure ck valve . . . . .

comments from the peanut gallery are solicited

Phase Two will be/is the construction of a 2-tube pressure jet/gold sucker
(already done, but I want to see how others address the suction with gravel ck valve)

 

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[RTR]

BillA I love DIY stuff, hope it works better than this

 

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[BillA]

RTR, set the bar a bit higher perhaps ?
not gonna make a silk purse from a sow's ear

 

[deserdog]

An observation, made while using a 3" super gold sucker to feed a sluice box. I used my 3" super gold sucker a lot to feed a sluice. I set the classifier at the head of the sluice. feeding this way will keep 2 guys busy, on sucking up material, and the other working the classifier. Each suction stroke of the 3" sgs will suck up about a pan full of material. 2 guys can move a lot of material this way. And better then using a shovel to move material from under water. Here is an old test I made, using a 3 sgs, pictures showing the pans sucked up and the oversize left on the classifier.
http://s244.photobucket.com/user/deserdog/library/3%20inch%20super%20sucker%20test

 

[N-Lionberger]

I made a super sucker after seeing one in use in one of Reed Lukens videos, I rarely use it as it isn't often I can find a suitable location for using it, its about 60" you get setup right it can be a comfortable operation. Years ago I tried making a sucker device with check valves it was a frustrating experience it worked great until the check valves wouldnt seat from sand hanging out on the lip. A fellow in the club had made one where he had glued weights onto the flappers to fight it but at that point I had given up on mine.

 

[deserdog]

I made the 3"sgs in barrel lengths from 36" all the way up to 60". I used a 36 barrel 3" sgs. I would set up my sluice after sampling an are I wanted to work, shovel into the sluice box until I got down to the water line, then switch over to the 3" sgs. The 3" sgs works great . After sucking up the material, you just give it a little twist, and this will keep all the material inside until you point it down. If you have ever seen someone moving material from underwater with a shovel, when you see water flowing off the shovel, gold is going too. With a sgs, you can easily move material from where it is sucked up to to either your bucket, or sluice, without losing any material. I prefer right to the classifier at the head of my sluice if possible, I hate handling material twice!

 

[BillA]

a 2-tube jet/suck gravel pump (la chupadora doblada)

a somewhat crude prototype in 1 1/2" with a mechanical agitation probe added
simple concept, the pump cylinder is filled on the suction (back) stroke and as the stroke is reversed the ck valve on the suction line closes while the ck valve on the discharge (jet) line opens
(the discharge/jet line is ported above the presumed level of entrained fines - hope so)



the window in the side of the lateral is to observe the ball ck valve in action
below is a beveled end w/o a ck valve



if someone wants to build I have tons of info

 

[BillA]

deserdog, I think my use of the phrase "sand pump" for this device is imprecise, your sgs is more in that vein. You and GnS are using the pumped lift water to transport the solids, whereas I am recirculating the fluid - discontinuous and some make-up water required if a 'dry' crevasse.

will post photos of a 2" and discuss the 3/4" suction tube problem in several days
also the wet weights of various models (the weight/performance benefit tradeoff)

 

[BillA]

(vertical) ball check-valves

4 sizes, and some considerations regarding their use



as noted previously, I elected to use locally available materials so the 3 suction tubes are 1/2" CPVC, 1/2" & 3/4" PVC sdr pipe
- the smallest suction tube, ~3/8" ID, is al to maximize the ID vs OD in a longer tube
al tubing was scrounged to fit the suction tube ODs and 3 sections cut out to make the cage to restrain the ball
(pln the far end, attach w/PVC cement for removal if needed)
a better cage could probably be made with ss fine rod, and tubes of al

one needs to ensure that there is adequate space around the OD of the cage for the largest pebbles/rocks to pass freely away from the ck valve
clearance problems become apparent when attempting put larger tubes into smaller bodies,
as even with the tube inlet orifice pinned a pebble can come up and out the ck valve which cannot fit into the gap in the annulus between the cage OD and the fitting/tube ID
below is a sectioned 2" lateral with the 3/4" ck valve in place, side and back clearance are the same -> too small for 3/4" suction tube



I am rebuilding the 2" lateral into something with a 1/2" larger ID (with a window), trying to get by w/o going to 3".
here is a section with the 1/2" ck valve for comparison



I prefer the suction tube discharge end to be just below the branch centerline.

 

[et1955]

Great job, creating is so fun, I'm making a trommel right now, good luck

 

[BillA]

Great job, creating is so fun, I'm making a trommel right now, good luck

indeed, designing and then building and then using is an excellent intellectual experience
did one understand their concept, and have an idea how to do it; were alt methods evaluated, was the actual design improved ?
was it built with more mods, and tested and improved some more; where is the point of diminishing returns for more 'improvements' ?
good fun

 

[BillA]

well, a setback - or opportunity . . . . .
after taking the photos in post 28 above, I was forced to address the suction tube diameter issue

I started building these PVC suckers with a threaded connection on the tube to facilitate changing diameters and unplugging and found immediately that the suction tube volume was limited by the pump volume, i.e. a larger/longer tube necessitated a larger pump. I started with 1/2" CPVC and 1/2" PVC to which I then added 3/4" PVC; the pumps were 1 1/2" and 2" diameter and the DWV laterals were the same. A 2" pump on a 1 1/2" lateral (suction/separation body) worked very well, so obviously 3" pump needed to be put on the 2" body. Worked well, but getting heavy.

However the 3/4" suction tube, with the bigger pump particularly, would lift larger pebbles than could clear the gap between the lateral ID and the suction tube OD, and worse with a ck valve atop the tube. I have a 3" PVC DWV lateral and it is HUGE, I will not carry.
So I am rebuilding the 2" laterals into 2 1/2" nominal IPS with acrylic to watch the action. DIY to the max here, think epoxy.

later

 

[Bejay]

I like Tnet member Bejay's idea that is quoted below.

"I have always used a 2 inch shrimp gun. It does not capture and hold material like those you must empty each time. Rather; you suck and shoot the material immediately into a low sided plastic lug*. Then you simply can pan or sluice what you have accumulated in the lug. The most notable concept is the suction plug; which is a rubber ball on threaded stock compressed between a washer and a nut on each side of the rubber ball. The rubber balls are available as replacement ones if needed...but after many many years, all I have had to do is tighten the bottom nut/washer compressing the ball if the suction plug gets weak. I like the handle set up as well. I can often keep up with a two inch dredge for short spurts till my lug is full.

Bejay"

*Submerge this next to where you are working.

Check this link if you are not familiar with the shrimp gun. https://www.google.com/search?q=shr.....69i57j0l5.9327j0j7&sourceid=chrome&ie=UTF-8

I tend to always carry my shrimp gun, a pan and a lug. One year while I was wintering and mining down in Az we had a week of heavy rains, and water was flowing throughout the deseert washes. So I grabbed my shrimp gun and headed out. Quite a few other miners/prospectors saw me using it. Long story short: I had my office secretary go to the local Bi Mart Store and buy 18 of them and she sent them down to me so others who wanted them could enjoy the fun. Not having to empty the tubes allows one to really clean out pockets and crevices.....and if a sluice is set up where you are working you can shoot the material right into the sluice. Having been a dredger for 40 years I sold my backpack dredges long ago and simply use the shrimp gun. I have a very small creek coming down the side of a mtn from an old hydraulic placer working and each year in the early spring I can work the 1 foot wide creek running down over the bedrock and get as much gold with the shrimp gun as I can working a 4 inch dredge on my claims.

I had a guy come do some yard work for me the other day. He saw a lot of my mining gear and took an interest in "finding gold" . I gave him a shrimp gun and the very next day he was down on a couple of known "gold producing creeks" hi-grading the bed rock pockets. Another friend bought one and found some nice gold on a river "not known for gold" just a few weeks ago. Cheapest gold producing method I know of. All one has to do is practice using it (suck and shoot) and know where to go hi-grade the bedrock.

PS: If you watch the vid on "how to make the shrimp gun" be advised you don't have to glue the end cap on the tube. It fits tight enough that you can pop it off if and when you want to re-do the suction plug (rubber ball or ?). Just make sure you make the tube long enough that you don't hit the end cap with each pull.

The ready made shrimp guns I buy have a handle off the side....and they were a mere $20.....so I don't bother making them. Bi Marts sold them cheap. http://shrimpguns.com/shrimp-guns/
Bejay

 

[deserdog]

They really do work great. In this case, simple is a lot better!

 

[63bkpkr]

Bejay or anyone - the above link to H2O sports is dead (it will not allow me to send them a message) any other suggestions?..........63bkpkr

 

[Bejay]

I went to the link and it allowed me to purchase them. Other than that I know the Oregon Coast Bi Mart Stores carry them.....and you could talk to them if you wana talk!.


Bejay

 

[BillA]

well complexity strikes again (better now than later), but I am beginning to wonder when this odyssey will end

The suction tube head annulus needed to be increased to accommodate the maximum gravel size lifted thru the 3/4" tube, one consideration.
The other consideration is fluid velocity, which is what provides the lift in the suction tube;
and a certain velocity is required to maintain the particles in suspension - no different than a dredge.
Where the produced water and solids exit the verticle ck valve (post #28) it is desired that separation occur immediately to drop the solids.
The higher the upwelling velocity, the greater will be the fines lifted by the flow (same as in the suction tube).
Note that at the level of the ck valve the upwelling fluids will equal the solids being dropped, not so large a volume.
Maximizing the volume at the level of the ck valve seems worthwhile.

I am concerned about upwelling entrained solids in the pumped water as that water will have to pass a 3/4" poppet ck valve with ~1/8" clearance.

cutting and bonding, The Frankendredge

 

[Bejay]

I guess I fail to understand why everyone wants a check valve..... and to hold the material in the tube so you have to take it apart to empty it into your . If you can suck it up and squirt it right back into a tub or sluice you do not have to take it apart and empty it; and it is really an easy efficient method of cleaning out crevices, pockets and cracks. Granted you can't lallygag in between the suck and shoot but I would contend I can get far more done in less time and clean out a crevice faster than any other hand method. 40 years of doing it has proven it produces the desired outcome. Simple works!

But I always see the complex systems being discussed.

Bejay

 

[deserdog]

I agree Bejay. The kind of gold sucker I started using originally was the one that is in Sam Raddings book of plans. And I have used the straight pump(shrimp gun) and the super gold sucker(shrimp pump with a 45) Simple, easy to use, and can get a lot done.

 

[BillA]

rest easy guys, simple is always better - no argument here
where one can suck and discharge - why do any more ?

I am designing/building a tool to do something a bit different as I have no convenient discharge.
The stream is a 150'+ rockface mostly covered in moss @ ~60°, where I wish to extract the material and then pass it down.
The flow varies from very low to a torrent not approachable (12' rain/yr), so the ultimate sucker (for this application) will recirculate the water.
a bit different than suck-and-dump, hence the effort

edit: as I am in CR there is no buy option, it is only DIY