I glassed on these fins with epoxy. It was a hot day and I miss timed the narrow window in which it is possible to cut away the excess material with a razor blade. Now everything is rock solid and all sharp and pokey.
What would be the best tool to clean up these fins quickly?
Grinder, then hand sand.
Thanks Barry. I’ll start with the grinder. Would you yourself go with hand sanding as the next step, or a disk sander? I shaped the fins with a Milwaukee sander using a 6" power pad. I am a little worried about ruining my pad, though. Is that why you recommended hand sanding instead?
If you attack the outer edge of the fins, it will heat it up some. You may be able to cut with razor blade. If not, you will be thinning it out and take it back to the original fin shape.
Before you use grinder, try heating with a heat gun. You may be able to trim most of it off. Then grind fillet down it ends of the fin.
Yes, fins will “F” up a pad real quick.
A nice sanding block and some 60 or 80 grit will bring them back to shape.
I like to use my rubber sanding block for these applications.
Dremmel the outline with a carbide cut off wheel or drum sander sleeve then hand sand
I would hit the leading edge with a sanding disc on a grinder… The backside with a rolled up piece of sandpaper (only 'cause I don’t own a dremel).
I was all set to start off with the grinder but a few pulls of the trigger led me to think that it was just too powerful. I feared that one slip would mean certain destruction of my fin and/or board. After digging around my shelves I found this thing (see image below). I don’t even rember what it is called. It has a little vibrating saw blade that cut through the fin material quite well. It only took a few minutes to get it down to the state as shown below.
Note that in hindsight this was probably the wrong tool for the job – from an economic perspective. The little saw blade is now so dull it won’t cut anything else. Barry’s advice above was probably the best approach. Next time I’ll just suck it up and use the grinder.
I am now finishing it up with a sanding block. It is actually going faster than I expected, and I see no need for the disc sander. I spray glued some 60 grit to a little 1" round plug of resin, which allowed me to sand the trailing edges. I had to stop before finishing though. Hopefully, I can finish it up tonight.
That tool is known in the carpentry trade (in NZ anyway) as a “Multi-Tool”. Very useful for blind cutting of skirting boards, architraves, decking etc as well as for cutting nails to release weatherboards. You can get titanuium blades for them that last a long time. At any rate a dremmel would have been the duck’s nuts. I have also used a grinder with a diamond cutting disc in it to do this job. You can buy diamond cutting discs for $20 here in NZ so I imagine they’d be even cheaper in the US.
You wound up using the tool I was going to suggest. Called a multi-tool or “finecut”. They have triangular and teardrop shaped sanding attachments for those. Mine is a Rockwell and it came with both sanding pads, plus a few different grits of each type paper. The triangle pad with some 60 grit works well for sanding at the fin bases, among other uses.
I have a little pad that is about 5".
It is a Power Pad I wittled down while it was spinning on my sander.
Great for fitting between glass-on fins when sanding.
That spot directly behind front fins and the front of the rears is a bitch area to sand.
Small pad is helpful.
Like Barry
with a lot of work to do a 5" or so.
I have a 3"
but hardly use it as it is
kinda insane on a Milwakee sander.
IMHO
I like a small pheumatic grinder with a rubbler sanding disc about 2" or so.
All about throddle control
but you can get in there
Eh and not blow your good shuff up…
Spray glue, 60 - 400 paper
Saves a lot of sand paper!
Best
From Harbor Freight I’ve been using Dremmel bits that look like a pencil lead with grit on one end. Draw a cut line, run the bit along that line. Works great with very minimum vibration and wrenching damage to the work.
