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Peel ply question
- Thread starter Sig600
- Start date
woodmanrog
Well Known Member
The whole purpose of
peel ply is to soak up residual epoxy and leave a perfect surface to apply more glas if need be. Your layups should only have enough resin in them as to make them transparent. In other words, don't get too carried away with the epoxy resin.
peel ply is to soak up residual epoxy and leave a perfect surface to apply more glas if need be. Your layups should only have enough resin in them as to make them transparent. In other words, don't get too carried away with the epoxy resin.
Just install the peel-ply slightly larger than the lay-up. Then you will have something to grab.
Why would you use tape and peel ply for an emp tip seam?
Tape is usually 8oz fabric or higher, and has one selvage edge and one woven edge. The heavy fabric weight is thick, and the selvage edge is even thicker. The result is a raised strip (0.010" to 0.020") which will be obvious unless (a) faired over a large area with a lot of filler, or (b) sanded heavily, or (c) both.
A recent accident report listed mass quantities of filler on a control surface as a possible contributing factor. Enough said.
Heavy sanding makes the peel ply application pointless. Heck, it makes the heavy tape pointless.
The lightest control surface (most flutter resistant for the least total weight) will be the one with an exposed seam. If you wish to hide the seam, do so using the least possible material.....which isn't a heavy tape strip and the filler to hide it.
Tape is usually 8oz fabric or higher, and has one selvage edge and one woven edge. The heavy fabric weight is thick, and the selvage edge is even thicker. The result is a raised strip (0.010" to 0.020") which will be obvious unless (a) faired over a large area with a lot of filler, or (b) sanded heavily, or (c) both.
A recent accident report listed mass quantities of filler on a control surface as a possible contributing factor. Enough said.
Heavy sanding makes the peel ply application pointless. Heck, it makes the heavy tape pointless.
The lightest control surface (most flutter resistant for the least total weight) will be the one with an exposed seam. If you wish to hide the seam, do so using the least possible material.....which isn't a heavy tape strip and the filler to hide it.
Dan, this is the process/result I'm trying to mimic:
http://rvbuildershotline.com/articles/2009/emp_tips/index.html
http://rvbuildershotline.com/articles/2009/emp_tips/index.html
RV7Guy
Well Known Member
Right and Wrong
I'm the author of that article on the glass work. Dan is somewhat correct if you use the the wrong tape. I advocate using a very light tape which has very little edge.
Because of my RC background I'm very familiar with the lightweight glass cloth. The tape I'm referring to is 2 oz tape that is .003 thick!!! There is virtually no edge at all. http://www.cstsales.com/glass_tape.html I use 1" wide.
For this application I have used ply peel but it isn't 100% necessary. You can apply the tape and blot any extra epoxy with a paper towel with nearly the same results.
If using ply peel, you'll find it can occasionally tear. If you start to get a tear, lightly heat with a heat gun and it will come loose easily.
I'm the author of that article on the glass work. Dan is somewhat correct if you use the the wrong tape. I advocate using a very light tape which has very little edge.
Because of my RC background I'm very familiar with the lightweight glass cloth. The tape I'm referring to is 2 oz tape that is .003 thick!!! There is virtually no edge at all. http://www.cstsales.com/glass_tape.html I use 1" wide.
For this application I have used ply peel but it isn't 100% necessary. You can apply the tape and blot any extra epoxy with a paper towel with nearly the same results.
If using ply peel, you'll find it can occasionally tear. If you start to get a tear, lightly heat with a heat gun and it will come loose easily.
Darwin, thus far I've followed your write up to the letter. Even using the .003 from CST. I couldn't sand the initial filler under the joggle down quite as much without losing the flat surface, but I got it as thin as possible prior to laying down the glass. Just one strip, just like the article. Great write up BTW.
