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Bottom Rudder Fairing Advice

1949MGTC

Active Member
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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
 
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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).
 
Sioux RS10K recip saw with 32tpi blades, and a 3M 5444 "Stickit" sanding board w/ 60 or 80 grit paper.
 

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Dan Horton

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.
 
I used a dremel sawmax to make the initial cut, then a piece of 60 grit sandpaper wrapped around a 1/2x1x12" piece of wood to sand the edge straight.
 
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.
 
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Best way to cut fiberglass

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.

https://www.boschtools.com/us/en/boschtools-ocs/cordless-oscillating-multi-tools-23521-c/

https://www.boschtools.com/us/en/bo...ti-tool-cutting-accessories-osl312f-142610-p/
 
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