(The most efficient gold getter.)
Some of you have hit me up via e-mail asking me why I seldom (if ever) write anything about suction dredging. It's a valid query and here's my two-part answer: 1) I don't dredge anymore, and 2) suction dredging is on its way out in the West and Southwest, never to be seen or heard from again. If you weren't aware of the latter you soon will be...trust me on that. Despite all this, I've put together some basic tips about suction dredging that may prove useful to you, so read on.
The Main Advantage
Of all the pieces of small-scale mining equipment you could possibly use the suction dredge is, by far, the most efficient gold-getting device out there. That's my opinion anyway and I base that statement on my own use of a suction dredge for many years and direct observation. Unlike power sluices (highbankers) and trommels, the suction dredge provides the opportunity for working both shallow and underwater locations that would normally be off limits to other types of motorized gear. Therein lies the dredge's main advantage...and a huge advantage it is. Without suction dredges (the huge barge dredges not withstanding), those hell-bent-for-leather underwater miners you see sucking gold off the ocean floor near Nome, Alaska on TV would be shit-out-of-luck. Ditto for small-scale miners in California and Oregon who are pretty much S.O.L. these days anyway. You see, the gold-bearing rivers they target are best worked using...yep, you guessed it...a suction dredge. I know this for a fact because I used to dredge a major auriferous river in Northern California each season. So I know of which I speak. Anyhoo, all this stated, suction dredging is dying a slow and painful death in California and Oregon, with other Western states to follow suit as more time goes by. You can thank the green cult crazies, the dope-smoking tree huggers, and those perennially spineless California politicians with their hands out (Jerry Brown included) for this assault on the basic rights of small-scale miners. Like a well-known conservative radio personality likes to say, "Liberalism is a mental disorder." And guess what brothers and sisters? The crazies are now running the lunatic asylums in California and Oregon.
Now that I have that off my chest (temporarily anyway), let's get on with the business at hand. Here are a few dredging-related tips for you:
1) Ask yourself if the return is worth the cost. Suction dredges are NOT cheap. Brand-new ones will run into the thousands of dollars and even decent used dredges will cost you a pretty penny (although you could probably pick one up relatively cheap in California or Oregon these days, no joke). Coincidentally, it takes time to get up to speed operating a suction dredge. So if you're relatively new to the gold mining game, buying an expensive suction dredge is not gonna be your best move. Even if you're an experienced miner this may be true as well. You have to be working stretches of water frequently enough and with enough gold in them to make your time, effort, and money worthwhile. If not, then all you're doing is laying out boo-coo cash for an expensive mining toy that you'll only use once in a blue moon. On the flip side dredgers like our Dominican Republic buddy Eduardo Herbert are working spots that are rich in gold, including nuggets and coarse gold. In a situation like Eduardo's the dredge costs (purchase and operating) are more than compensated by the return (just take a look at some of his recent photos here for proof of that fact).
(A 153-gram nugget recovered by dredger Eduardo Herbert in the Dominican Republic.)
2) Stay away from suction dredges if you're a greenhorn or newbie. This admonition follows hard on the heels of Tip 1. Although relatively basic in their overall engineering and design, suction dredges can be complex pieces of mining equipment for anyone unfamiliar with their operating principles and most effective deployment. This is true is right from the get go and is then amplified by the lack of experiential knowledge like deploying a dredge in real-time stream conditions, especially underwater. So you newbs and greenhorns take note. Wait until you get more knowledge and gold mining experience under your belt before trying to suction dredge. Otherwise, you're just wasting time and money, and posing a safety threat to yourself (and perhaps others). Once you've gained some expertise and actually know how to use a gold pan, sample, run a sluice box or even a dry washer, then maybe it's time to think about taking a stab at dredging, hopefully under the direction or tutelage of someone with dredging experience. Be patient, learn the pre-requisite skills, and then get to dredging. Anything else just doesn't make sense.
3) Do your maintenance. Like any other piece of motorized machinery, suction dredges require a certain amount of maintenance to keep them operating at peak efficiency (or operating at all, in some instances!). Maintenance can be preventative, predictive, or corrective (or at least that's what it is where I work), but for the most part what you'll be concerned with is preventative maintenance (keeping bad things from happening) and corrective maintenance (fixing or replacing things when they stop working or break) on your dredge. One huge preventative maintenance item to remember dredge-wise is making sure you have a clean air filter in good working condition and perhaps a spare or two. Other dredgers will tell you to only change the unit's air filter once a year (or once a season, that is) but I'm suggesting that you check the filter once a week when you're running hot and hard. This may sound excessive (and I do get a bit paranoid at times!) but I'd rather take the brief time to look at the air filter than replace the entire dredge engine somewhere down the road. Also, before the dredging season starts you should have already identified any worn or suspect-looking parts or dredge components and repaired or replaced the same. Nothing's worse than getting to some remote gold location; humping your dredge, gas, and supplies in; and then having a worn part or component go bad on you or break.
(Part of Eduardo's dredged nuggets for the last three months.)
Mind thy dredge oil level. It's never a good idea to run a new dredge engine for more than five hours before changing the oil. This helps break the new engine in. Also note that dredges typically don't use oil filters so you have to change the engine (motor) oil more frequently...say every 30 hours or so. Some people suggest an earlier oil change but I think 30 hours of continuous running is about right. Oh, and don't futz around buying cheap-ass oils or motor oils that aren't designed specifically for your type of dredge engine. Spend a few extra bucks so that you can sleep well at night knowing that suction dredge of yours is going to suck gold up like a "champeen" come the morrow. You get what you pay for, after all. Oh here's another thought about dredge engine oil. God help you, man and woman alike, if by some poor chance of fate you leak a bit of that engine oil into that gold-bearing stream or river you're working. If you do manage to escape being immediately strung up by crusading greenies, the other forest Nazis will make damn sure you pay for your sacrilege, maybe even confiscate your dredge. Anything's possible these days, after all is said and done.
There's more to come on suction dredging. Until then, love one another other if you can and barring that...well, be kind to one another, OK?
(c) Jim Rocha (J.R.) 2015
Questions? E-mail me at firstname.lastname@example.org