Blocked Conduit - Need to See in 3/4" Conduit - Fibre optic Camera?

I have a 3/4" Conduit that seems to be blocked at the end. We can kind of hear the Fish tape tink at then stopping point, though we don't know where it is... We don't know how to locate the end of the conduit. We were thinking if we could see the end, it might help us determine the location. It is about 6'-8' to the end of the conduit. I've tried looking for Small Cameras, but nothing that will really fit in the Conduit. Found a bunch of Borescopes, though they are too expensive.

It would be great to get something like this:

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Though 97cm is too short.

Any Suggestions on how to see to the end or find the end?

Thanks!

Reply to
Scott Townsend
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Uhh... pull the tape out and measure it? What's in the conduit now, and where does the conduit go?

Reply to
Goedjn

Trick we have used on water pipes: Take a carry tank and connect hose to conduit. Blow 100 psi air thru and search for the "whistle" at the other end.

Alternate: pump Mercaptan in with the compressed air and locate by smell.

Jim

Reply to
Speedy Jim

The conduit is from a Pull Box to a Driveway pillar. Nothing in it now. We want to Light the Driveway Lights, though cant seem to figure out how to get there from here, The Fish tape does not come out anywhere to connect up to the lights.

Reply to
Scott Townsend

Reply to
Scott Townsend

Air good, water bad...

Who pulled the conduit?

Reply to
dpb

Its been installed in the Driveway pillars for years. That whole planning for the future thing. Just now getting to it.

Reply to
Scott Townsend

one can always abandon the old conduit and run new.

g adds. MONEY , what a concept

Reply to
macaca

Just noticed a mention of the lights in an earlier post I hadn't previously seen--are they already there or is there an indication where they're to go? Starting from the other end might lead somewhere? Not being able to see the situation makes more really specific ideas difficult. Is the distance the tape is going near the end point that you could actually be hitting the box cover? If it's way short, perhaps the conduit just terminates? All kinds of possibilities rear their head not knowing what actually have...

At this point if I was adamant to get something working I'd probably do something similar to the other suggestion of essentially starting from scratch from the end of the run, knowing at some point I'd have to find the existing run coming back....

Reply to
dpb
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Yes but if you're using a wire fish tape, then you shove it in one end until it hits something, then you pull it out and measure how much tape went into the conduit. That tells you how far away the blockage is, and with any luck, you'll be able to figure out roughly where. (this assumes no bends that you don't know about.)

Then you'll know where to dig, or what to take apart to clear it. Have you tried running the tape from the first pillar? That would give you another data-point.

--Goedjn

Reply to
Goedjn

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Cheapest thing out there (ready to go), but at 7/8" too big for 3/4" conduit. Plenty of smaller mini cams out there though the small dia ones don't have internal LED lighting so you'd have to rig something. One of the 1/2" dia mini cams paired with some 1/8" plastic fiber optic cable and a light source mounted behind the cam could work. Attach the whole thing to the end of the fish tape and push it in.

Check distance to blockage from each end with the fish tape to see if it's a small blockage or a big problem like a section crushed by a loaded cement truck.

If you think it's just a rock or bit of cement, attach a pointed chisel to the end of the fish tape and see if you can bash through it.

Pete C.

Reply to
Pete C.

According to Scott Townsend :

Aside from the suggestions of measuring how much fish tape goes in the pipe, are you _sure_ it's actually blocked, and not just the end of the fish tape running into an elbow or something?

Old trick: tie a piece of string to a ball of cotton batting, and blow it thru.

Reply to
Chris Lewis

Hi, thanks for your post. I was looking (puzzled, really) at borescopes, and the lack of reviews. (Well, there was one Amazon.com review on the Provision 3000, kinda' negative) and only saw this one, for the relatively expensive Hawkeye. Borescopes seem to range from $120 to $3000. Here's the text from the review (product reviews) I located with some trouble, with Goggle:

Through the looking glass: Gradient Lens Corp.'s affordable Hawkeye[C] borescope is a fascinating and useful tool - but like Alice, your life may never be the same after you peer through this looking glass Guns Magazine, May, 2002 by Holt Bodinson

Looking down bores and chambers, into locking lug recesses, inside loading dies and brass cases, isn't for the faint-of-heart. You often discover things you wished you never knew about. But using a Hawkeye [C] borescope quickly becomes addictive. And using it when buying used guns or analyzing mechanical problems can save you the original cost of the borescope many times over. (Just imagine approaching a table at a gun show with a borescope tucked under your arm.)

Let me give you a few examples from my own experiences of using the Hawkeye borescope.

Is It A Bargain?

A pre-'64 Winchester Model 70 Featherweight in .243 Win recently hit my dealer's used gun rack. The metal and wood were in great shape, and looking down the 6mm bore with my naked eye, the rifling appeared to be clean and crisp. I happen to like both the caliber and the model, and I decided to make an offer. But before doing so, I asked for the opportunity to examine the bore with the Hawkeye. Glad I did. What appeared to be a decent bore turned out to be an eroded one from the throat to the muzzle. We're talking about that cracking, alligator skin-type condition that is often seen in the first few inches of the bore forward from the throat, but rarely all the way to the muzzle. The .243 was totally shot out. I passed on the piece and pity the fellow who ended up with it.

After cleaning another .243 -- a Ruger 77 with a pristine barrel -- I checked my work with the Hawkeye borescope. Looking down the barrel, everything looked clean until I hit the mid-point. There, for a distance of about 2 inches, were lumps of copper jacket material still adhering to the lands. I couldn't feel any constriction at that point with a patch or brush. With the naked eye, I certainly couldn't see the fouling. Yet, there it was, bathed in a brilliant copper light through the lens of the Hawkeye. A few passes with Sweets 7.62 solvent and it was gone. Mystery Solved

I was puzzled by the lack of accuracy shown by a No. 1 Mk III Enfield that had been factory reconditioned at the Ishapore Armory in India. The piece looked absolutely brand new, yet it wouldn't group as well as an original 1918 BSA. Out came the borescope. Throat erosion from the spaghetti-like strands of cordite powder has to be seen to be believed. It takes the form of a many-pointed star or a series of little mountains and valleys in the throat area. Both Enfields exhibited throat erosion, but the barrel of the rebuilt rifle exhibited an erosion pattern extending from the throat to mid-bore whereas the erosion of the 1918 BSA bore was largely restricted to the throat itself. Puzzle solved. Without a borescope, I would still be assuming that the barrel of the rebuilt Enfield had to be in better overall condition than that of a 1918 antique.

I have a .308 Win across-the-course match rifle sporting a premium-grade stainless-steel match barrel. It's been a fantastically accurate target rifle and the current barrel has seen in the vicinity of 2,500 rounds down its tube, many in rapid-fire events. Borescopes make it possible to monitor bore wear, and I was curious. What I discovered with the Hawkeye was not a great deal of wear, but a very visible machining chatter mark about mid-bore. Given the quality of the barrel, it really did puzzle me. This might have well been one of those times when "ignorance is bliss." That chatter mark has not affected accuracy or accumulated fouling or had any other effect on the performance of the gun, yet psychologically, I now wish it weren't there.

And revolver barrel throats!!! Don't even look -- or you'll be picking up the phone and ordering a throat reamer kit from Brownells within the hour. The same goes for the reamer marks in modern revolver cylinders. I've even used the borescope to look for and locate burrs in the hammer slot of a frame.

In shotguns, the Hawkeye borescope really gives you a bird's eye view of how well you're doing in removing plastic and lead fouling from the chamber, forcing cone and choke. It also permits you to see how well any factory aftermarket choke tube mates with the interior surface of a bore and whether or not the tube is flush with its threaded seat when fully tightened. You can study the length and degree of finish of forcing cones and the design of fixed chokes.

When cleaning, the borescope permits you to objectively evaluate results as you test various chemicals, brushes, abrasives and cleaning protocols.

Did I say the use of a borescope is "addictive?" Once you own one, you'll be poking and probing into every firearm in your collection, discovering new uses every day as you do so.

Designed For Industry

The Hawkeye Precision Borescope is the creation of the Gradient Lens Corp., located in one of the optical capitals of the world, Rochester, N.Y. The Hawkeye Borescope is just one of a sophisticated family of optical examination instruments produced by the company that are used in industry to check the quality of everything from fuel injector nozzles to interior welds.

The Hawkeye borescope consists of three units: the borescope with attached eyepiece; a right angle mirror tube that slips over the borescope and rotates 360 degrees; and a Mini-Maglite light source that screws into a fitting at the eyepiece and serves as the handle. In use, the Mini-Maglite is screwed into the borescope; the right angle mirror tube is slipped over the borescope shaft; the light is turned on, and you're ready to take a look. The borescope can also be used without the rotating mirror tube, providing forward image viewing and is useful for examining the internal flashhole of a case, for example.

What is unique about the Hawkeye unit is the lens system. The makers have been able to eliminate the cost of grinding, polishing, coating and centering numerous micro-lenses normally associated with this type of instrument by substituting a series of short, optical glass rods or "gradient index lenses" that relay the optical image from the objective lens to the eyepiece lens. The resulting images are bright, color correct and very sharp. In fact, the depth-of-field of the Hawkeye extends from 1mm to infinity.

Gradient Lens Corp. offers two models of the Hawkeye.

There is the original model that features a fully adjustable focus with all the components packaged in a lockable custom metal carrying case. Normally selling for $760, Gradient is currently offering a $60 discount bringing the price down to $700.

The Big News

The real bargain is the new "Limited Edition" Hawkeye selling for $495. This model is exactly the same as the more expensive original except for the focus adjustment of the eyepiece, and the metal carrying case. In the original model, focus is adjusted by turning the eyepiece with nothing more than your fingers. In the "Limited Edition" borescope, the focus is factory set and I found it perfect for viewing; however, the eyepiece can readily be re-focused by loosening three small hex set screws and moving the eyepiece in or out. Frankly, given the extended field of view offered by the Hawkeye, the need for changing the focus should be minimal. For example, when viewing the large interior of a shotgun bore, I find that positioning the lens tube against one wall of the barrel provides a crisp image of the opposite wall.

The only other part of this optical system that is nice to have, but not essential, is the snap-on, right-angle eyepiece, which is offered as an accessory. When you're dealing with a bolt-action rifle with a high Monte Carlo stock, it's difficult to position your eye behind the eyepiece as the lens is fully inserted. The simple solution I found for most bolt-actions is to lay the rifle on its side when using the Hawkeye. The right-angle eyepiece sells for $275 and is offered for a reduced price of $195 if purchased with the more expensive model. If you're working primarily with modern stocked rifles, I would strongly recommend the purchase of this one accessory.

The borescope of the Slim model is 17 inches long and approximately .165 inch in diameter. The addition of the rotating mirror tube increases the probe diameter to .188 inch so it will work in any bore size from .22 through the shotgun gauges. In use, because of its

17-inch length, the lens tube is inserted from both the breech and the muzzle to view the entire barrel. Of course, in the case of most lever-action rifles and autoloaders, you're limited to viewing from the muzzle unless some degree of disassembly is possible. Autoloading and pump shotguns pose no problem since their barrels are easily detached.

For the professional gunsmith or barrel maker, Gradient Lens also offers Hawkeye compatible accessories such as video cameras and monitors, digital cameras, and high-intensity light sources.

The Hawkeye Borescope is a remarkable exploratory and diagnostic tool for the firearm owner. Its optical quality is superb, and its use is simple and straightforward. From a cost point of view, the Hawkeye is no more expensive than a quality pair of binoculars or a rifle scope; plus, it can save the owner many times its original cost when evaluating potential purchases over the years. And, yes, it's addictive.

Chris Lewis wrote:

Reply to
tunesandballoons

measuring how much fish tape goes

I use a plastic grocery bag tied to thin nylon line and use a shopvac to suck it through the pipe.

Using a blower or vacuum is a good way to help diagnose what's going on with the conduit. Attach the blower/vacuum to one end and see if you can feel the air moving at the other end. If you don't feel anything, you have complete blockage.

Have you tried using a plumber's snake to see if you can work that through? If you have 90 degree elbows on the 3/4" pipe, save the effort - the snake won't make such tight turns. I always use sweep elbows when I'm running buried conduit and 1" is the minimum size conduit.

R
Reply to
RicodJour

Whats going on when you run the fishtape from the other end.?

If its 6'8 from the end............

You may have had a coupling come loose. and its dead ending somwhere.

PVC or metallic?

I went over to a guys house that ran me some conduit underground before he poured the concrete ( he was trying to save a buck or two) and he installed plumbing 90's which rendered the pipe pathway useless.

measuring how much fish tape goes

Just dont put you ear up to the other end if you are blowing unless you want and earful. lol

Reply to
Tazz

Put a blasting cap on the end of the fish tape. Use a large enough one and you will either clear the pipe or blow a hole out of the concrete.

Reply to
Terry

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