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Building Tips and technical articles. => Building techniques => Topic started by: Dennis Toth on August 12, 2017, 12:12:37 PM
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Guys,
Anyone have a method for getting a straight, fray free, cut in 1/2 oz fiberglass cloth? I'm going to use it to add strength and stiffness to my Barnstormer 1/8" elevator. This ship has a tube and wire full length hinge (alternating sections of 3/32" brass tube about 3/4" lengths), I want to avoid getting the glass down into the hinge area so would like a nice straight cut. One way I thought might work is to take a piece of blue masking tape the length of the piece and put it on the glass. Then use a new razor blade to cut through the glass and tape. Then I would put a very thin coat of epoxy resin on the surface (craping off the excess). Then laying the glass/tape in position on the elevator with the tape/cut edge along the hinge line. After this cures I would remove the tape and finish the glass with another coat or two of finishing resin.
Anyone know a better way?
Best, DennisT
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Spray where you want to cut with hair spray. Let it dry then cut. Edge is nice and clean.
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Guys,
Anyone have a method for getting a straight, fray free, cut in 1/2 oz fiberglass cloth? I'm going to use it to add strength and stiffness to my Barnstormer 1/8" elevator. This ship has a tube and wire full length hinge (alternating sections of 3/32" brass tube about 3/4" lengths), I want to avoid getting the glass down into the hinge area so would like a nice straight cut. One way I thought might work is to take a piece of blue masking tape the length of the piece and put it on the glass. Then use a new razor blade to cut through the glass and tape. Then I would put a very thin coat of epoxy resin on the surface (craping off the excess). Then laying the glass/tape in position on the elevator with the tape/cut edge along the hinge line. After this cures I would remove the tape and finish the glass with another coat or two of finishing resin.
Anyone know a better way?
Best, DennisT
Dennis,
Don't screw around with tape. It will miss up the FG badly. (Don't ask me how know. OK, I did it and that was the result)
Get your self a "Rotary" Cutter. Here's a picture.
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Make sure that whatever tool you use is Scary SharpTM.
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Roll out the .5oz glass. Spray the lightest of mist coats of 3m77 spray from a couple feet above. Lay a piece of butcher paper over the glass. Cut your pattern out of the glass /paper composite.
Then apply the resin to the part you'll glass. Apply the glass/paper glass down on the resin. Let it soak in to the glass. Peel the paper off the glass. Smooth out. Done.
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Spray where you want to cut with hair spray. Let it dry then cut. Edge is nice and clean.
I give it a coat of thin dope which does the same thing as the hairspray.
When cutting make sure that the surface under the FG is soft enough so that the very tip of the blade passes through the FG (I use several sheets of newspaper, but card or even a cutting mat should do the job) This means you are not cutting with the very tip of the blade, but the edge - I use a new blade in a scalpel.
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Like what Gerald said, unless you are reeeeealy good with a pair of sharp scissors.
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Like what Gerald said, unless you are reeeeealy good with a pair of sharp scissors.
Peter,
I always used scissors also, but not for a clean edge, just to cut the cloth. I would just apply the glass cloth and sand after the resin cured. Where there was no resin, the cloth would remove itself by the sanding. Control the edge by where you would apply the resin.
CB
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Anyone have a method for getting a straight, fray free, cut in 1/2 oz fiberglass cloth?
Flatten it out, spray on a light coat of fabric sizing, then iron it on a flat surface. Then cut with a rotary cutter as shown.
Brett
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Targhet was almost on target.
If The goal is to laminate the balsa then the problem is that balsa absorbs a lot of resin.
3M77 and wax paper is the best way to maintain fiber orientation as you apply the fibers to the wood. But If you wet the wood you add a lot of weight to the part. Instead wet the cloth while is on the wax paper, blot off the excess resin while and apply this to the wood after that. This way it will minimize the resin content to be the max.
Just make sure the wood is free of dust. Skip this step and get ready for delaminations and grief.
As you can see is almost identical to what Targhet said the change is to wet the glass while is on the wax paper and blot out excess oposed to wheting the wood and apply the fiber on to the wet wood.
If you really want to wet the wood then us a small amont of resin on a roller, get the roller dry (roll on paper towels till it it is hard to wet the towels) and then apply the resin to the glass (I assumed the glass was placed on the wood with 3M77) before this step.
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Rotary cutter is the way to go. I got one at a fabric store and it works great.
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Target assumed that the surface to be glassed was already sealed, but in fact, it was likely not to be, depending in the builder.
Good point Traian....