Cutting GRP Sheet - Best Blade

[rosie]

I need to trim some 4mm thick GRP sheet with an electric jigsaw. Seeking advice on best type of blade for the task.
Thanks in anticipation.
Dave

 

[coopec]

I would use a metal cutting blade if you have one. But there are special blades you can get for cutting fiberglass.

Perma-Grit Jig Saw Blades in stock | Fibre Glast
Best Solution to Cut Finished Composites . Perma-Grit ® Jigsaw Blades are perfect for making large cuts or for cutting along flat sheets of laminate composites, like fiberglass and carbon fiber.

Jig Saw Blades - Saw Blades - Grainger Industrial Supply
When it comes to Jig Saw Blades, Grainger's got your back. ... Masonry jig saw blades are available with carbide or diamond teeth for cutting fiberglass, ...

 

[Fr J Hackett]

Use one of the proprietary blades, masking tape on the cut line top and bottom and your JigSaw should have a little plastic blade guide that fits in the fork around the blade, use it.

 

[macd]

If the cuts are straight, I wouldn't use a jigsaw at all: angle-grinder with a 1mm disc.

 

[savageseadog]

If the cuts are straight, I wouldn't use a jigsaw at all: angle-grinder with a 1mm disc.

For a bigger job, a reciprocating saw.

 

[PetiteFleur]

I've used both a standard metal cutting blade and the grit type. For a small cut then the metal type are ok but for prolonged cutting the grit type are best. I've got a Makita grit blade which is excellent, which I got because my local building merchant sold it.

 

[PuffTheMagicDragon]

If the cuts are straight, I wouldn't use a jigsaw at all: angle-grinder with a 1mm disc.

Ditto except that I use a stainless disk with embedded hard particles (diamonds? carbide?). These are sparsely distributed around the outer 8mm or so of the disk and are not like the grit encrustations that are sometimes seen.

 

[paulajayne]

I have fitted all the panels on my yacht rebuild with this:-
https://www.amazon.co.uk/dp/B01L70MM4S/ref=asc_df_B01L70MM4S51887709/?tag=googshopuk-21&creative=22110&creativeASIN=B01L70MM4S&linkCode=df0&hvadid=226152056294&hvpos=1o3&hvnetw=g&hvrand=16299078730636865794&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1006555&hvtargid=pla-578915428552&th=1&psc=1


Easy to cut straight and only have on minor failure on over 50 panels

 

[PaulJS]

I bought a dual blade saw specifically to cut a lengthy bit of fibreglass about three years ago... Haven't had a chance to try it yet!

 

[AndyL]

I have used these and find them excellent.
https://www.axminster.co.uk/bosch-t30chm-clean-cut-solid-surface-plastic-jigsaw-blades-503764

 

[rosie]

Thanks for all the advice - the job is a small curve so it will be a jigsaw job. I will try a metal cutting blade and protect the cut with masking tape as advised.
Dave

 

[lw395]

if the GRP is fairly 'lean' rather than awash with resin, I've found saw cuts to tear the material.
Personally, I would use a thin disc in angle grinder to get rid of most of the waste, then trim to size with a belt sander or, for internal curves, a drum sander in a B&D drill.
GRP is variable stuff, If what you're trying isn't working well, try something else.

 

[Graham_Wright]

Diamond loaded glass cutting blade. Works a treat and lasts quite well.