So I’m a newbie at fiberglass. What techniques and tools do you have for trimming the bottom rudder fairing down to the scribe line and how do you get it to be a perfectly straight line so it doesn’t look like a beaver chewed it?
I found that a Dremel tool with a diamond cutting wheel worked best for me on the fiberglass cuts. Then I used the PermaGrit tools and a 12" piece of 2x4 with #80 grit sandpaper attached to it using double sided carpet tape to smooth and straighten the edges after the cuts.
Just be careful to protect your skin and lungs while you are making fiberglass dust (sanding and cutting).
__________________ Dave Macdonald
RV-10 First Flight April 1, 2020. Phase 1 Complete 2021 VAF Dues Paid (plus a little more)
So I’m a newbie at fiberglass. What techniques and tools do you have for trimming the bottom rudder fairing down to the scribe line and how do you get it to be a perfectly straight line so it doesn’t look like a beaver chewed it?
Thanks
Bill
S12049
140849
Best advise. Read every thread Dan Horton ever posted. Especially the Sticky on Fiberglass.
I made a feeble attempt to collect and share the high points. On my blog there are pages for fiberglass, paint, etc. Lots of lists of stuff.
I cut with a Dremel outside the line. Shape a little with a Vixen file then smooth with a board and 40, 80 grit. Dan's methods are awesome.
__________________
Larry Larson
Estes Park, CO http://wirejockrv7a.blogspot.com
wirejock at yahoo dot com
Donated 01/01/2021, plus a little extra.
RV-7A #73391, N511RV reserved (2,000+ hours)
HS SB, empennage, tanks, wings, fuse, working finishing kit
Disclaimer
I cannot be, nor will I be, held responsible if you try to do the same things I do and it does not work and/or causes you loss, injury, or even death in the process.
Dan would say the green 3m long board 40-80 grit lasts pretty well, I would agree. But, I switched to Permagrit for making a lot of plenums.
Pricey for a few uses but unbeatable for a lot of edges.
BTW - I use the dremel with HF diamond blades for well cured glass, for green glass a more coarse wheel is required.
If I built another plane, permagrit (or that style) countersinks would be purchased.
To the lower fairing, Vans has us put the attachment strip under the bottom rivets. I sanded the inside of the fairing to get the thickness even then added a spacer to avoid sanding the fairing to fit. Some outside (gel coat) sanding was done as the gel coat has no strength anyway. This way it was butted even along the length. The attach strip may have to be bent as the (my) fairing was not square. A lot of little fitting.
I saw one builder that split the fairing so the aft section could slide off (taildragger) and reach the electrical. I might try that on the next one too.
__________________
Bill
RV-7
Lord Kelvin:
“I often say that when you can measure what you are speaking about,
and express it in numbers, you know something about it; but when you
cannot measure it, when you cannot express it in numbers, your knowledge
is of a meager and unsatisfactory kind.”
Use an oscillating saw with a 270 degree, round, fine tooth blade. Make a fence out of aluminum or wood, attach it to the fiberglass on the cut line with a hot glue gun and saw away. The kerf is 1/32”. Easy
I also used my Bosch oscillating saw to cut my canopy, works great and is very controllable.
Bottom Rudder Fairing Advice
Phase 1 Complete
Linear Mode
