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Grinding disc for Fibreglass

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I need to do a few odd glassing jobs soon. A few videos I’ve watched recently, guys seem to be using an angle grinder with a specific disc when bevelling the old FG in preparation for laying up new.


Does anyone know what type of disc this would be? I went back few some of them and can’t find the name mentioned.

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If you're feathering to stagger layers in like a scarf, use a stiff fibre backed disk on a rigid backer and use the old layers visually, like a topo map you're sanding thru, to get a  uniform taper. The rubber rigid backer come with all grinders & fibre disks are $1.50 each. " Norton brand"

  Finish with a flat glue on/velcro disk at lower speed. If you're careful you probably wont need the flat pad. Any automotive paint shop has them, M10, bunnings etc. Don't use more than 80 grit for good mechanical key.

Lay you're largest piece of glass  first then progressively smaller to get thickness you require to avoid sanding thru your long fibres. Avoid overbuilding and creating a hard spot. (stress riser) Hot coat neat resin

to fill weave.

Peel ply is your friend.



Oh, and always have the direction of spin going away from edge or you'll end up wearing the grinder.

I  mostly use adjustable speed, sander /polishers for fine work; 11000rpm mini grinders for bulk.

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I won't add to the actual work. Lateral has great advice.
But I can suggest ones look at trying the "Blaze" discs. These are the flexible type ones that need the rubber hard back unit to give them backing. Blaze are bright orange and are a cubic ceramic material that is sharp as heck, last a long time and cut awesomely. I use them on SST all the time now. Also available in flap discs and other forms.

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