2" vs 2 1/2" dredge

[happyharvick]

Hi all, I'm looking to purchase my first dredge. The creeks I work don't have much water so I can't run anything bigger. I was wondering is a 2.5" worth being almost twice the price of any 2", does the 2.5" run that much more material than a 2"?

 

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[enamel7]

You can definitely move more material with the 2 1/2. Best bet would be to look for a used one at a lower price.

 

[spillercanyon]

Yes. You can compare the material a dredge can move by comparing the area of the nozzle end, pie (I don't know how to make my keyboard type a pie sign) radius squared.
2" dredge has an area of pie (2 * 2) = 4 pie
2.5" dredge has an area of pie (2.5 * 2.5) = 6.25 * pie
Since pie is common on both, it can be eliminated, giving an area of 4 vs. 6.25 or in other words, the 2.5" can move 1.5625 times as much as a 2" dredge. That is if all material can pass through both, with the 2.5" allowing larger material, you may experience an even higher ratio in the field.

Good luck!

 

[GoldpannerDave]

Looking at location the dredge is to be used is important, too. Do you have to pack it in or can you basically open the back of a truck, pull the dredge out and easily move it to water? I have worked both a 2" and a 2 and half incher before. The 2" was a backpack dredge and easy to move into the location and the 2 and a half was NOT. It was an old heavy unit, but once on the creek, it outperformed the 2 incher.

What type of gold are you going to be dredging? Do you need air (likely not in a shallow creek), but I don't know of any 2" dredges that have air; very few 2 1/2 have it.

 

[AlaskaGold]

Get a 2.5 inch. You will be happy to carry more weight or take two trips to get it to the over over that many more rocks you will have to hand chuck out of the way. If you have low water you can always try one of those hydro force nozzles. I have not run one but have seen others use them with really low water with success. I'm thinking of getting one for my 3 inch to clean bedrock that is above the water line in the middle of some of the creeks I dig on. Good luck with the new toy and take lots of photos!

 

[goldgit'r]

Buy a Dahlke 2.5 micro dredge and solve both problems!!!!

Wes

 

[Hoser John]

Correct formula is pi-3.14 x radius squared so-3.14 x 1 x 1=3.14"sq. VS 3.14 x 1.25 x 1.25=4.9" sq. Therefore over 50% more volume into the nozzle AND a lot less rock to chuck and tire you out. Less plugups and always use a nice blaster nozzle to get it on as smaller units don't move much and need all the help you can get. Just about anywhere you can run a 2, a 2.5 is easily doable-John

 

[spillercanyon]

Hey John, looks like I needed a bit more coffee yesterday, yes, radius not diameter, thanks for keeping me straight (if that's possible) and for sharing all the great info. pi, 3.14, can be dropped since it is on both sides of the formula, thus 1 x 1 = 1, 1.25 x 1.25 = 1.5625, thus 56.25% more capacity.

 

[Reed Lukens]

Buy a Dahlke 2.5 micro dredge and solve both problems!!!!

If I wanted a small light weight dredge then for sure I would buy the Dahlke 2½ because for size I think it is the best portable 2½ on the market.
Check out the link - 2.5" Micro Midjet -- Dahlke Dredge

I had a 4" Dahlke and it was garbage that year when they had a bent jet but the 2½ Dahlke mid-jet has been my favorite small dredge for a long time. The riffle system is no frills from the looks of it but it really catches the gold with a couple simple mods and tweaks here and there. It weighs 50lbs total as is so you can easily carry it in all at once when it's packed right. Here is an old pick of my son Abe running the 4" Dahlke when he was 12. Then Abe running the 8" by himself when he was 15> I raised my kids with gold mining and now I'm raising my grand kids gold mining.



This is my grandson Ryden highbanking and sluicing with us from this last summer on our family claim. And then with Rodney teaching him how to fish. So we have 3 generations of California gold miners shown here of the 10 total generations of California gold miners from our family.

 

[Prospector70]

How do you clean out that little Dahlke? Do the riffles slide out, or do you rinse it down into a tub?

Reed, I love those pics, very nice!

 

[goldgit'r]

You just pull 2 pins and the riffles and carpet slide right out, rinse in a tub and right back in!

Wes