JOG:

I have made some scrapers from thick plexiglass, and they worked great for removing old weathered silicone calking from the seams of my trailer.  I would spray some window cleaner on the seam for a lubricant, then use the plexiglass scraper to wedge the caulking off...the glass cleaner allowed the scraper to move along the painted aluminum surface without scratching it.

I have also made scrapers from Ebony wood that work really well.  Both the plexiglass and Ebony need to be sharpened fairly often - but they don't gouge or scratch anything.

Well,, heres what Ive learned so far.. and it aint good..

First, the scroll saw blade cant ditch the heat or handle fiberglass,, it rubbed the teeth off & got so hot its slack now,, OOPSIES!!

The cut off grinder creates a Nasty smelling cloud of fiberglass dust.
Ive got one side almost flattened,, so, I am almost 1/3rd of the way to having a working scraper & have to run away to breathe & its bothering my eyes..

In closing,, Ive decided that
Number 1: Ive never been unable to successfully scrape a surface
w/o a fiberglass scraper
and

Number B: I dont need one badly enough to go thru the BS of building it.

Im calling it a fail ,   :'(

I kinda wish I hadnt cut that thing up,, POOT!