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QuickTalk 10 - Q-TIPS

I live in a cold climate, so I figured a way to have ventilation without heat loss in my shop. A friend loaned me a squirrel cage fan and I installed it in my window. A plastic 1/2" flexible tube (the one I used to level the fuselage) was attached to the output of the fan. At the other end I glassed the hope to a rubberized dust particle mask. An exit hole was drilled at the mouth and siliconed to a thin plastic flap valve for exhaled air. I patched a small tube from the hose into some protective eye goggles for fresh air and to prevent fogging. For better control, I hooked the fan into the hot wire voltage regulator. Now I have a cool refreshing way to work, especially on long layups and in closed quarters such as the fuselage. (From Chris Buhler, #2593)

The plans should include a reference to mount any antennas PRIOR to glass layups. (From David Naumann, #2803)

I have found that using RAES (slow) epoxy system on a large layup gives 2-3 hours of tack-free working time. This allows plenty of time to squeegee off excess epoxy for a light layup. (Bill Merritt, #203)

Much time has been devoted to discovering the best tools and methods for sanding. I am surprised that I have yet to read of anyone using my approach. Basically, I use a Surform file handle but NOT with the rasp blade - it is far too aggressive. Stanley makes "Permanent Sand Paper" blades in course and medium grades to fit the handle. Essentially they bond carbide bits to a sheet metal backing. I keep two handles, one with each grade. They last forever and are easily "unloaded" (premature sanding) by a wire wheel on a grinder with no ill effect. Have found that none of the file handles are truly flat. Some careful belt sanding makes them perfect. I then use 2" abrasive cloth from "shop rolls" in 60, 80 and 120 grit, etc. depending on the requirement. Each block is a 1/2"x2"x10" bar of aluminum stock; the working surface ends slightly radiused. The strip is torn off in approximately 14" pieces and wrapped tightly lengthwise on the block. Two 3" pieces of duct tape hold very well. I use one block "hard" as is and one with a dense 3/32" adhesive foam strip on the working surface. These work very well on all surfaces including compound curves. The abrasive cloth is also easily bonded via a Plio-Bond (Goodyear) to 6-8" tubes of a various diameters to work various fillets. (Paul Yarnall, #2021)

Of all the template materials suggested, I found that 1/4" "tempered" Masonite is ideal. Aluminum and plywood are expensive and hard to work with. I recommend "tempered" Masonite since the regular is too soft. (J.H. Schenck, #2784)

Regarding the comment about Burt Rutan's "squeegee-stop-inspect for bump" method (QUICKTALK #8, page 9), I took in one of Burt's seminars at Oshkosh last year. On a fresh layup of cloth with liquid resin already squeegeed all over it, pull your squeegee longways with fairly firm down pressure. Any liquid resin that builds up in front is called the "bump". This indicates you have too much resin and excess weight. If more cloth is required, add it and stipple. Check again. If no more cloth is to be added, remove excess resin by squeegeeing off the edge. (Tom Angell)

How many people have pipes in the attic uninsulated? The picture of the trough-cutting hotwire (Issue #7) inspired this thought of using leftover long foam pieces. Determine pipe size in attic, square up two foam pieces and cut semicircular trough in each piece. Cover the pipe with the "insulation" and strip of duct tape. Check the price and see! (Mike Conlin, #60)

This tip will make post curing the canard a relatively simple job. Basically you convert your jigging table into an inflated dome hot air tent using household hair dryers and poly vapor barrier sheet. Obtain a piece of heavy (6-8 mil) poly sheet 20' long by twice the width of the jig table. Staple and tape the plastic to the sides of the table. Gather the ends and tape to the table ends, leaving a 2" air inlet at one end and a 2" vent at the other. One hair dryer is attached to the air inlet and used to keep the plastic dome inflated. This alone will only raise the temperature 10-25 degrees C, depending on heater size, air leaks, etc. The other hair dryers are put entirely inside the hot air tent, so that they re-circulate and re-heat the air inside the bag. They should be arranged so that the airflow follows a "race track" course inside the bag. This will ensure that the air is turbulent and well mixed, resulting in even heating. The hot air from all heaters should be directed away from the canard to avoid local hot spots. Ensure that there is about 6" clearance between the bag and canard all the way around. Three 1000-watt hair dryers are sufficient to obtain a 140-160 degree F temperature. On some models you may have to bypass the overtemperature cutout (usually a bi-metal strip). If you bypass the cutout temporarily, try and use only the low or medium settings. You can use industrial type hot air guns, however, you must be careful to direct the hot exhaust AWAY from the canard and put a fan in the bag to insure adequate circulation. The exhaust of these guns can exceed 400 degrees, so proceed with caution. Even if you buy two cheap hairdryers for $10 each, it is still cheap insurance for post curing your $2000 canard. DO NOT USE RADIANT HEATERS inside the bag as they can result in local hot spots and melted styrofoam. Use hot air heaters only! When beginning, bring the temperature up slowly. Monitor the bag temperature at several spots to insure even heating. Control the temperature by enlarging the air outlet hole or unplugging one of the heaters. (Bob Falkiner, #2015)

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