Q-talk 6 - Q-TIPS
- Category: Q-Talk Articles
- Published: Saturday, 31 October 1987 06:11
- Written by Jim Masal
- Hits: 892
From SHAP Talk: Silicone contaminations on fiberglass parts causes paint adhesion problems. A good solution is adding Dupont Fisheye Eliminator to the paint. It comes in capsules that are mixed one per pint of finish material (available at Dupont auto paint stores). You will discover also that the finish flows out better which leads to a smoother, glossier finish.
From the Osprey Newsletter: After a year of flying his Osprey on auto gas, a builder found that TOLUENE, a very strong, flammable solvent that some oil companies mix with their gasoline, was softening his fiberglass tank. "I had noticed that it was hard to see the fuel level lately in the sight slots, and I found some brown glops when I was checking the sump. I think I'll pay the extra 50 cents a gallon for Avgas..."
From J. H. Schenck, El Paso, TX
Cold Weather Epoxying: Prepare surfaces for glassing as usual. An hour or so before working, I set up 1 or 2 clamp lights with 75W bulbs, adjusting distance from the surface so that it's just warm to the touch (2 lights will warm about 2 square feet). Mix epoxy in a heated area (or you can use a hairdryer carefully directed into or around your cup - ED.), apply, then reposition lights so as to keep the area warm but not hot or the foam may melt. Check after a short while to be sure you have the right heat.
From Mac Perryman, Jena, LA
After my bottom wing layup cured, I installed 1x4 boards onto short cross members with Bondo. The boards were level both parallel and perpendicular to BLOO. When I turned it over, it laid flat on my level work table and required only minor adjustments.
From Dave Naumann, Ft. Rucker, AL
Liquid firewall will harden if you spray over it with high temp auto paint and put it out in the Alabama sun for a couple days.
The NTSB investigator confirmed to me that Bob McFarland's wing delaminated over the spot where he used 2-part pour-in-place urethane expandable foam. The glass does not stick to this stuff like it does to Styrofoam. Don't use it for large structural repairs.
The NTSB investigator told me of a Quickie fatality caused by painting a stripe on the wing leading edge. I thought everyone knew this was a no-no.
Bob Bird #2556
Trying to get the Nylaflow tubing to lay flat against the inside of the wheel pants so you can glass over it with the required two BID is very difficult when installing the brake system. Try drilling 1/32" holes 1/8" apart and running a short piece of safety wire through the holes from the outside to secure the tubing. Do this in a couple of places and it will hold the tubing flat 'til the glass cures. Wiggle the wire 'til it breaks. It will break on the inside of the pants leaving very small holes to repair with micro.
From T. J. Wright, Somerset, PA
1. To easily layup aileron and elevator slot cores, prop the cores with wet/dry micro as required then let it tack up a couple of hours. When tacky, rough cut your BID and wet it out in place on top of 3-5 mil thick plastic. Cut the BID, plastic and all, to proper width +2 inches, invert it into the slot then peel away the plastic all in one operation. The tacky micro will hold the glass in position to allow peeling away the plastic. Brush/squeegee all voids. All 4 slots on canard & wing plus rudder slot can be done in an hour.
2. A 1200-watt hairdryer is just right to apply LIGHT local heating to wet out cloth and get excess resin to the surface where it can be squeegeed off or blotted with paper towels. Keep the hairdryer moving to avoid hot spots that will melt the Styrofoam.
From Jim Masal, Editor
A couple of tricks from the Glassair guys:
1. Modeling clay from the 5&10 is cheap and excellent for holding parts in position while 5-Minute or other epoxy cures. If you don't have 5-minute, Bondo will do the job just as well.
2. It's handy to lay up 2-3 plies of BID as a flat sheet of stock. You can use this to cut out mounting tabs, stiffeners, etc. which you can tack in place then lay up additional plies onto for required strength.
3. If mounting something in a difficult area, smear on a spread of clay, press your object in position and the clay will show the location of bolt holes, etc.
From Jeff Cox, Arlington, TX
1. Wicks Aircraft Supply part number FRC-1644 is a new fire-retardant coating that swells (intumesces) when exposed to heat and flame, forming a thick, insulating barrier which prevents the penetration of heat to the underlying surface and prohibits the spread of flame along the coated surface.
2. I bought a Sears belt sander and then found their belt sander finishing stand (catalog #9 HT 25966) that the sander mounts to. This combination has saved me enormous time in sanding small parts.
3. If you can swing it, a compressor and air tools are the way to go. I found a small air tool similar to a Dremel (a die-grinder, ED.) which is much more powerful, has a number of different drum and disc sanding attachments and is a real time saver.
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