Body shell cutting Q

[BugMan]

Just been working on my scuttle, and can see some cutting in my very near future, and I've never cut this sort of stuff before, so looking for advice on best way and required tool's etc?

Already have flat-nose drills so that part is covered its the cut outs I'm worried about.

Was wondering is a 1/4 power file would be a good idea as long as you file away from the gel coat. 

[Andy (Sycho)]

Yep a power file is fine as long as you use it in the correct direction, also a Dremel is very handy I did 90% mine with one.

Prepare for dust getting everywhere 

[wizzer]

I found plenty of masking tape , normal hole saws on fast speed don't push to hard just let it do its thing ,on bigger holes like exhaust you can hole saw and sand it with a flap wheel type sanding tool to your marks/line .on smaller holes with normal hss bits i found blunt ones worked best or drill in reverse .

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F282543880941

Tony

[Dave Eastwood (Gadgetman) - Club Chairman]

I tend to find hole saws used with the drill in reverse have less chance of snatching and chipping at the gel coat.

Powerfiles work really well, as do Dremmels. Multi tools if you happen to have/have access to one are good too, though not something I’d buy just for GRP work.

I used to use the Dremmel with a cutting disc, followed by  sanding drums, now for anything but the smallest areas, or areas with lots of tight curves, I tend to use the cutting disc followed by the power file. - depending on belt grade and cutting speed, they’re excellent for both course material removal, and fine shaping/linishing.

[Peter (Monty)]

I like sanding drums on a rotary tool, as they as go with the grain of the laminate. For cutouts I'll usually drill the corners with a 10mm Brad point drill bit (which scores the outside of the hole first). Then I connect the holes with a cutting disc on the rotary tool and sand as needed to finish.

I recently bought a new rotary tool as my Dremel gave up the ghost. I think Dremel have lost their edge and are expensive vs lots of well-tempered competitors. I got this one from Amazon, it was pretty cheap but came with some excellent accessories and has worked really well so far.

[Alan Cutler (Adge) - Dorset AO]

Found Dremel with cutting disc worked fine. Mark where you want to cut on masking tape, and off you go. You can clean up any edges/corners with sanding drum in Dremel, can get different sized drums.

For larger circular holes, found a cone drill worked well.

I rigged up my workshop extract to suck up the dust, worked a treat. You could do the same with a vacuum (just don't get caught if it's the house one ). Also have a powered respirator/mask, which I found good for my own protection.

[Dave Eastwood (Gadgetman) - Club Chairman]

I’d agree on the Dremmel’s, the actual cutting and sanding attachments seem great still, but the actual tools seem to have lost their way somewhat over the last few years.

I’d  be tempted to go to one of the big diy chains and buy their own brand tool with a bullet proof guarantee if it does do belly up.

[Andy (Sycho)]

I brought one from B&Q in a clearance sale a own brand pro & it was dirt cheap. It’s still going strong after 15 or so years.

[BugMan]

Just used my Dremel with a cheap small flap sander, and it worked a treat with my vacuum hover behind to try to catch the red dust. 

[Thrustyjust]

Step cone saws were a revelation for holes and also the exhaust I used decent hole saws, not that do everything kits and was great. I used a dremel and cutting blades which also made life easy for cutting stuff. Then used emery cloth for finishing.

[Andy (Sycho)]

45 minutes ago, BugMan said:

Just used my Dremel with a cheap small flap sander, and it worked a treat with my vacuum hover behind to try to catch the red dust. 

Don’t remind me of that pink dust, I still find traces of it now.

[SootySport]

I use a jig saw (with metal cut blade) for straight and curved cuts and hole saws or normal twist drills for holes.  

  Mask both sides of the panel, measure 10 times and cut once as per usual, finish of with wet & dry or Dremel.

[Dave Eastwood (Gadgetman) - Club Chairman]

6 hours ago, SootySport said:

Mask both sides of the panel, measure 10 times and cut once as per usual, finish of with wet & dry or Dremel.

And never, never, never take any dimension for the position of cutouts, or templates for cut outs at face value, without comprehensively measuring and ensuring that they are suitable for your car.

It is the nature of many of the parts, that none critical dimensions can vary with considerably more tolerances than you may be used to from modern production cars. In addition, it is common to move panels etc around slightly to obtain “best fit”.

All of this means that there are very few solid dimensions on a Westfield that can be used as a datum to measure from. What might be perfectly correct and accurately measured one one, or even a dozen cars, might be 50mm out on your own.

Always, always check before cutting, especially if other parts depend on the accuracy of the hole’s location or shape.

[Robin Parker (Red Spider) - Yorkshire AO]

What is it you're needing to cut? 

If it's just a bit of fitting, you should be ok with hacksaw and files, holesaws are fine and use Blunt drills, a sharp one will bite and rip and chip the gelcoat. 

For bigger cuts, I use this at work.