Silkspan as a fiberglass veil

[Tallman]

Silkspan and Japanese tissue are great for balsa strengthening and finishing, but I was wondering if anyone has tried it for a better finish over heavier glass. Usually a much lighter glass -- say 1-2 oz -- is used but it's often a pain to work with (I'm talking flat fins here, not tubes or serious curves). The reason is weight: silkspan is smoother than even the light glass and less filler is less weight. For that matter strong tissue might work -- or nylon stocking material -- anyone tried something like this?

 

[amarillo_rocket]

I've used it on RC planes and it works great but this was on bare balsa. Get a scrap piece of wood, fiberglass it and lay the silkspan on top the FG for a smooth finish. If you like the finish that's all that matters.

 

[Astrobuf]

Silkspan and Japanese tissue are great for balsa strengthening and finishing, but I was wondering if anyone has tried it for a better finish over heavier glass. Usually a much lighter glass -- say 1-2 oz -- is used but it's often a pain to work with (I'm talking flat fins here, not tubes or serious curves). The reason is weight: silkspan is smoother than even the light glass and less filler is less weight. For that matter strong tissue might work -- or nylon stocking material -- anyone tried something like this?

I have used silkspan to reinforce rocket fins and rocket glider wings for 40 years now. It works very well. It has become very difficult to find the airplane dope paint that I use to mount and fill the silkspan. It is fairly available online from rc supply we sites. Brodak carries both light and medium weight silkspan and a good inventory of dope colors and thinners etc.

 

[G_T]

Fiberglassing is usually done nowdays with laminating resin - an epoxy. Epoxy doesn't stick to nylon. I doubt epoxy sticks to silk either. I'd use something else. There are non-woven fabrics made for this purpose. Don't expect them to impart any real strength though, and they are a bit of a sponge for epoxy. Unless you are vacuum bagging, I'd avoid.

There are a number of ways to use very light fabric fairly easily.

Spread out your fabric on a workbench, and using a soft wide brush, brush from middle towards edges to straighten the fabric fibers out.

When happy, use a spray can of 3M77. Stand back a few feet, and aim a foot over the top of the fabric. Spray a quick pass, and let the mist settle on the fabric.

Then take lengths of wax paper, and lay them on top the fabric. You can brush them down if you feel the need.

Now you can mark on the wax paper side, and cut pieces out (carefully) with scissors or knife or roll-knife.

Keep the fabric dry of epoxy. Have the surface that will receive the fabric wet out but not sopping. Lay the fabric side down on the epoxy surface. Get a corner of the wax paper free - an exacto knife helps here. Then rip the wax paper off quickly. Quickly is the key. If you try to do it slowly, you WILL fail.

You also don't want to roll or push down the fabric enough for the epoxy to get through to the wax paper, or again you will fail.

So there is a bit of a learning curve, but otherwise it is a good technique. I used it a lot many years ago.

But for smaller pieces light glass is easy enough to deal with. The above technique is particularly useful when working with 3' sections of light glass or Kevlar...

Gerald

 

[G_T]

https://www.fibreglast.com/category/Surfacing_Veils for those who are interested.

Gerald

 

[SolarYellow]

Wonder how much bagging that carbon fiber would do compared to papering fins.