assembly and operating instructions for blower models of ...mankelforge.com/mankel proof.pdf · of...

3660 Pillon Rd.Muskegon, MI 49445(231) [email protected]

Assembly and Operating Instructionsfor Blower Modelsof the Mankel Gas Forgewith Refractory Drying Instructions

39938 operating instruct.indd 139938 operating instruct.indd 1 6/30/09 4:39 PM6/30/09 4:39 PM

Photo 1 is a forge assembled and ready for operation. Notice how far the gas pipes are turned in. These pipes have to be turned in at least 2-3/4 inches (see photo 2) into the top of the cast iron mixer manifold. If not turned in far enough, the gas will be blown out the end of the manifold before it has a chance to ignite.

Photo 3 is a complete gas manifold assembly with brass mixer and orifi ce installed. The gas manifold will come apart at the unions (arrows), so it can be turned into the cast iron mixing manifold.

Photo 4 shows the adjustable regulator with dial handle turned out

and pressure gauge installed. With the handle turned out, the regulator will have a positive shut-off. Handle should be backed off when the regulator is installed on a tank and when changing tanks. Turn the handle in to raise gas pressure. The higher the gas pressure, the higher the operating costs. Mankel forges, regardless of the liner

type, operate the best at two to eight pounds of gas pressure, depending on your location (atmosphere) and what type of work you are doing. For example, a forge usually running on two to three pounds of pressure may be turned up to six pounds to forge weld. The pressure should be used as

an indicator, and you should make your fi nal adjustment on the forge by the appearance of the fi re.

Photo 5 shows a blower with the draft gate installed. Mankel gas forges do not need bottled oxygen to operate. With the use of a blower to force atmosphere oxygen into the combustion chamber and to mix with the gas, the forge will give you a hot, economical fi re to heat horseshoes or other metal. With a proper mixture of gas and air, you can forge weld with the Mankel gas forge. The draft gate should be used to regulate air fl ow. If you cannot get your forge to burn evenly, you may have to drill a hole in the end of the manifold. The hole or holes should be drilled in the end of the manifold, where the fl ame is burning away from the top. Too much air pressure causes the fl ame to jump away from the burner. Properly adjusted, the inside edge of the burner hole in the top will become a bright orange-to-yellow. NOTE: On three-burner manifolds, an air gate has already been installed. If the fl ame closes to the end doesn’t burn evenly, you may have to open or close this gate to get all three fl ames to burn evenly.

Photos 6 and 7 show the same forge with different adjustments. The only difference on photo 7 is that the draft gate on the blower is opened further. With the draft gate open that far, the forge in photo 7 had too much air, and therefore burned cold.

It may take several minutes foryour forge to get up to optimum working heat. A well-adjusted fi rewill burn with a bright blue fl ame, and, in a few minutes, will start to

Photo 1

Photo 2

Photo 3

Photo 4

Photo 5


heat the liner to a bright yellowcolor. With Mankel gas forges, MORE IS NOT ALWAYS BETTER. Too much gas pressure or too much air will make your forge burn colder instead of hotter. Use the setting fi gures provided as a guide to setup your forge. Each forge willburn differently, depending on atmospheric conditions in yourarea. If you still seem to be having problems getting your forge tooperate properly after double-checking all your settings, pleasecall and talk to us at 231-766-3582.

Now that you have some idea of what your Mankel gas forge will do, let’s back up and begin again. You have a gas forge in a box and no gas. If you do not know a bottled gas dealer in your area, look in the Yellow Pages for one close to you; ask if they will work out a lease or loan with you. Some propane dealers will do so. Alternately, Mankel gas forges will operate with a 20-pound propane tank, like the ones used for most campers or gas grills. One thing to keep in mind: the larger the bottle, the better the operation. Propane gas is a cold gas and will freeze if drawn from the bottle too fast. Propane bottles come in various sizes and it is a good idea to have a spare bottle on hand.

Install a regulator on the tank or bottle of propane. Remember that gas threads are a left-hand turn. Turn the gas piping into the mixing chamber on the cast mixing manifold. Hook up the hose. Check to make sure all the pipe connections are tight. When tightening unions, two wrenches should be used. Turn off the brass valve on the gas manifold. Turn on the bottle. Screw in the dial control knob.

Set pressure at three pounds. Now turn the bottle off. If gas pressure holds at three pounds, you have no leaks between the bottle and the forge. If pressure drops off, you will have to check for leaks. The best way to do this is with a leak-tester you can purchase from a welding supplier (one brand is Winton). With the gas turned off, paint all threaded unions and parts with the leak-detector. Turn the gas back on and check for bubbles. The leak detector will bubble where there is a leak. Turn the gas back off and tighten the leaking union. Then repeat the process and if there are no bubbles and the pressure holds when the gas is turned off, there are not leaks. NOTE: Many of us formerly tested for gas leaks using diluted dish detergent. The Federal government has determined that this can be fl ammable and has recommended use of a fl uid designed to be used as a leak-detector instead. This can be purchased at any welding supply store.

With the gas valve on the gas manifold turned off, you should not have a buildup in the forge. We recommend the forge be lit using a lighter designed for lighting gas grills, with the gas turned on. You may also use a lit match or spark light, but the gas grill lighter keeps your hand back away from the fl ame. A properly adjusted Mankel gas forge should look like photo 8.

Photo 9: If a match is held near the holes in the brass orifi ce with the forge running, it should draw the fl ame off the match. If it doesn’t the pipes should be pulled out and cleaned with wire, pipe cleaners or a small brush.

Photo 6

Photo 7

Photo 8

Photo 9


Natural Gas: Mankel gas forges will operate on natural gas. If you want to use natural gas in your shop, contact your gas company fi rst. You need to make sure that your gas company can supply at least six to eight inches of water column pressure for your forge to operate properly. At least a one-inch supply pipe is required to supply enough gas volume. Additionally, a forge set up for natural gas requires different piping and orifi ces than one that uses propane. Hopefully you informed us of that choice before your order was placed so that you have the proper fi ttings.

Reliner Kits: Replacement liner kits can be ordered when necessary. Small patches can be made with just repair mortar and a piece of the soft fi rebrick. Break off a small piece of brick and smash it into a powder. Mix in a little water and some mortar until a nice paste is formed. Pack the paste into any holes or bad spots in the forge liner. Allow a full 12 hours to dry. Larger areas will require a reliner kit with replacement insulation board and/or fi rebrick. After using repair mortar, any leftover mixed mortar can be stored by pouring a thin layer of water over it in a tightly-sealed container.

When using it again, mix the water with the mortar. NOTE: When large areas (three inches or greater) are patched, you must perform the refractory drying operation again.

IMPORTANT! THE REFRACTORY MUST BE DRIED OUT BEFORE INITIAL USE!

Why is this important? If the refractory is not dried out, a steam pocket will form in it and cause an explosion. The drying process also increases the life of the refractory.

TO DRY THE REFRACTORY OUT: Run the torches at low heat (no more than three pounds of pressure), without the blower, until the unit starts to steam (approximately 45 minutes to 1 hour). Shut off and allow the forge to cool. Repeat this operation, without the blower, several times, until there is no steam. Light the unit again at three pounds of pressure. Turn on the blower. Adjust the air gate so the fl ame is blue (too much air will cause the fl ame furthest from the blower to sputter). If the unit steams, shut it off and allow it to cool. Unit should now be ready for routine operation.

With a little care, you should get many years of usefrom your Mankel Gas Forge.

For a video of a properly burning forge, please see our website: www.mankelforge.com

For all products and questions, please contact:

Black Bear Forge3660 Pillon Road

Muskegon, MI 49445231-766-3582

[email protected]


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