Ironflight

Ironflight

VAF Moderator / Line Boy
Mentor
OK, so I have cut quite a bit of fiberglass in my RV ?career? so far ? trimming cowlings to fit for example. My usual tools are the cut-off wheel on a die grinder, and the 2? sanding disks on an angle die grinder ? they work quick, but do generate quite a bit of dust. I tried something new today - can?t remember where I saw a picture of someone using a set of shears to cut the excess flange off a cowling, but it was recent. I needed to do a little trimming on or pink cowl, so for an experiment, I picked up a pair of sheet metal shears, and nipped off a corner ? no cracks, perfect line, and easy to control. So I trimmed a whole bunch more ? boy, the lack of dust and noise was inspiring!

I still had to finish with a sanding block, and the parts of the cowl I was trimming were thin ? not sure how it would work on the thick stuff ? but add this little idea to your bag of tricks and give it a try the next time you need to trim some Van?s glass and the neighborhood noise curfew is in effect?.

Paul
 
I wonder if it will dull shears like it does drill bits? Probably not as quickly unless one is making fiberglass confetti.

greg
 
Greg Arehart said:
I wonder if it will dull shears like it does drill bits? Probably not as quickly unless one is making fiberglass confetti.

greg
Click to expand...

I actually did have the same thought Greg - I grabbed a pair of old shears from Home Depot to do the work. I don't think I'd use the expensive ones unless I knew they could be sharpened....
 
Greg Arehart said:
I wonder if it will dull shears like it does drill bits? Probably not as quickly unless one is making fiberglass confetti.

greg
Click to expand...

I use this trick a bunch up at the glider shop to rough-trim carbon and fiberglass, and it works a treat but does dull the shears a bit. As Paul suggests, I use the cheapie snips from Harbor Fright and the five-dollar bins at Ace Hardware.
 
A multi-function tool does a great job when working with fiberglass. The RV-10 has plenty of "opportunities" to work on your fiberglass trimming and finishing skills.

The Fein Multimaster is the gold standard, but I found that the inexpensive version from Harbor Freight does just fine and saves you about $300. The Harbor Freight blades ($7) don't last as long as the Fein ($50) blades, but with the price difference and how often it's used on the RV, the frugal route is the way to go.

With either version, there is very minimal residue dust. What dust there is, just falls to the floor and isn't kicked up into the air. This makes cutting fiberglass much more tolerable.

bob
 
Ironflight said:
......can?t remember where I saw a picture of someone using a set of shears to cut the excess flange off a cowling, but it was recent.....
Click to expand...
Paul,

You likely saw the picture of the shears among the cluster of images I recently posted on this thread:
http://www.vansairforce.com/community/showthread.php?p=538884#post538884

I've owned those never sharpened shears for several decades and a little fiberglass cutting on the RV hasn't seemed to hurt them a bit. Anyway, the proof is in the pudding....you found out for yourself how simple and dust free the process of shearing fiberglass can be!
 
That was it Rick! The image stuck in my mind, and the author didn't....Credit (and thanks!) goes to Rick for this one!


Paul
 
Jig saw for long cuts

I have also used shears for short cuts in the fiberglass.

For long cuts, I have found my variable speed Bosch jig saw with a fine tooth blade works best. Much more accurate and controllable than a cut-off wheel.

Not nearly as much dust and makes a very nice cut. Just did my first cuts on my top cowl.
 
Be aware, when you use shears, that you are cracking the resin around the cut. There are two remedies for this. Cut outside the line and final sand to the desired cut line (however, there's your dust again as well as the chance that you won't get rid of all the cracking) or dab some resin into the raw finished cut. Make it thin and it will wick in and seal the edge. I've also use cyanoacrylate (CyA or superglue) to good effect. I used shears recently on the empennage fairing for the RV-10 and only had to resort to a cutoff wheel at the thick, curved areas near the empennage leading edges. It was more the curve than the thickness that defeated the shears.
 
flion said:
Be aware, when you use shears, that you are cracking the resin around the cut.
Click to expand...

Right. The shears work grerat, but don't shear along the final line. Heck, you wouldn't want to even if the shears didn't crush the laminate. There's no way you can get a perfectly straight edge with shears, or at least not an edge as straight as you can get with an 18" to 36" sanding board.

Thread post from 2007, about 75,000 hits so far:

http://www.vansairforce.com/community/showpost.php?p=167693&postcount=14
 
HF Oscillating Cutter

I found it particularly easy to cut FG with a Harbor Freight high-frequency oscillating cutter. These are the ones where the blade doesn't spin (like a wheel) but instead, shakes back and forth at a very fast rate. I remember back in the day, when I was a kid that doctors use this type of cutter for slicing through fiberglass casts without cutting skin.

They work quickly, make very little dust, cut like butter and don't crush the resin way back into the cut, like the snips do.
 
+1 for oscillating cutter

I manufactured the orthopedic cast saws and the blades. Works on plaster, glass and carbon. However the devices used in the med environment have a little vacuum port built in the saw to suck the dust. Just FYI, don't do it in your paint booth LOL
 
Dremel Saw Maxx

I too have cut lots of fiberglass, carbon fiber, Lexan. By far the best too ever for this purpose is the Dremel Saw Maxx. Cuts Lexan like butter and doesn't create as much "snow" as the die grinder with cutting disc. More importantly it is very easy to control.

Shear might work for some rough cuts but would I would be concerned with crushing. Definitely will try for the early cuts.
 
Rough trimming fiberglass parts with shears is Van's recommended procedure in the RV-12 plans.

Step 2: Trim the tire opening of the U-00001A Wheel Fairing Front to 1/16 inch from the scribe line with hand shears. Finish to the
scribe line using a sanding block. See Figure 1.
 
I did my cowl (Pepto pink) with aviation snips, and was amazed how close you could get to the scribed line without damaging/crushing the fiberglass...maybe 1/16". You can also be ultra precise with the snips, which is more than I can say for my Dremel technique.

Then block-sand the edges and call it done. :)
 
Saw Max

RV7Guy said:
I too have cut lots of fiberglass, carbon fiber, Lexan. By far the best too ever for this purpose is the Dremel Saw Maxx. Cuts Lexan like butter and doesn't create as much "snow" as the die grinder with cutting disc. More importantly it is very easy to control.
Click to expand...

Which blade did you use for Lexan?
Which blade for fiberglass?
I may buy a new tool.
 
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