RC India

Any pointers on smoothing up coro? Coro cuts well and easy but edges are often dirty; Please share you experience and techniques in cutting coro while maintaining smooth edges...

You can neatly put cello tape round the edges.

If we are going parallel to the flutes, then cut the emerging small portion from the sharp hobby knife, touching the ends of the flutes.
We can smooth the edges if we go cross the flutes. In anyway we can smooth the edges. I always smooth the edges and its very easy.

@rastsaurabh. Thanks, I use vinyl strips mostly to cover the flute openings, but would really want my base to be superfine before I stick the vinyl strips on.

@swizera - Thanks, parallel is easy and works great, removing extra plastic with a paper cutter/hobby knife . It's the cutting across flutes  that needs finesse, especially when cutting curves :). What do you use to smooth? I've tried sanding with a no. 100 sandpaper; the results are pretty good, just that the coro filings remain stuck. I m also thinking of using a polishing stone used for polishing glass next. Will post my results.

First sanding with 100 grade sandpaper. Finish it off with a final sanding of 220 grade. after that is done, use a rough cloth to remove the stubborn particles remaining stuck.

If you are using a snap off blade, use 4 new cutting edges while cutting coro for a medium sized plane (wingspan around 1250 mm). The blades get blunt very fast, even faster while cutting depron.

Instead of trying to cut across the flutes or the curve at one go, use multiple cuts and exercise patience.

All the best.

Thanks @VC
The blades do blunt out quick. I will try finishing with no. 220 sandpaper and update...

GS

The Coro Cutting Method I use

# Place Coro on Large Glass Table top or light trace glass table. (No wood).
# Place Steel ruler as guide (As with line).
# Place the scale covered at the side which will be used and the waste side be opened.
# Press the scale with left hand and cut with 1/2" or 1" disposable knife sharp blade.
# Always your moving blade position should be such that the cutting position be between thumb and middle finger on scale, pressed.
# The direction of cutting should be such that it would get inward cut along flute  instead of outer. That meand, if the blade suddenly changes route along flute, it will be restricted by the Steel-Ruler.
# I just pull (wipe) blade tip in edges of Glass sheet and it agains up. When found useless, just cut a small with Plier.

Thanks

Thanks @kalyanprodhan -  :salute:
I use xactly the same method, all points diligently followed :)

Earlier when I was doing a variant of the spad deb, most cuts were straight. This time I had my eyes set on the cub and realized that cutting curves surely needs some finishing afterwards... I have only cut the vert and horiz stab yesterday using a burmester french curve, but still the edges were not as smooth as I expected :(

Or use a hot wire cutter..... you will get decent cuts.

hmmmm, thanks @rastsaurabh, will try sanding with 220 paper elsewise get hold of a hot wire cutter...

I cut the curves without any curve and press support. While cutting any curve, I complete generally in one stroke. However, the cutting edge angle be low and be sharpen before every cut (Except first) rubbing/wiping with glass table edge (Not Cleared edge, If you have clear edge, just rub with jewel driver, you will get the surface. Even you can do this in any glass bottle too.). It is better than sandpaper.

But preferably cut the curved surface at first. And always follow the direction such that dis-routing along flute cannot damage the job.

Thanks

To get a smooth edge i use the hot glue gun tip and glue to make it smooth... this not only gives smooth edge but puts strength too. same with the tape if i put it on the edges.

Scissors work great for cutting coro, be it straight lines or curves. I never use knife or blade for cutting coro. Get a good quality medium size  scissor and keep it dedicated just for cutting coro. You can also use the scissor to slit coro flutes.

I just use a shaving blade.... round cuts everytime

Sent from a potato using a lamp - now mashed