Correct tool for cutting into Fiberglass Deck

[rhtrades]

Does anyone have a recommendation on the best cutting tool(s) and blades to cut into Fiberglass non-skid Deck?  (I am replacing my deck core). 
Would an angle grinder work well?
Thanks

[RickK]

Most people use a skil saw and slide along the bottom of the liner. It leaves about 1.5-2" lip all around. Angle grinder will get the job done but you'll be all over the place with it.

[rhtrades]

Thanks Rick.  And would a metal cutting blade work well?    Also, do you have any recommendations on a brand of gel coat?   

[RickK]

I don't know how a metal cutting blade would do. Any blade you cut fiberglass with is going to get trashed. The deck is mostly balsa wood with glass on both sides, so a wood cutting blade is what I used. I bought my gelcoat at a local supplier, it came in a white 5 gal pail. Not sure it had anything but their store name on it since they buy in bigger qty and break it down into smaller qty.

[rhtrades]

Thanks Rick. 

[msteinkampf]

I tried a variety of oscillating blades, but none of them cut very effectively. I wound up using a 4.5 inch diamond blade for my angle grinder. Dewalt DW4701.  It’s marketed for cutting concrete. I cut out my entire deck, and it didn’t seem to dull the blade at all.

Expect a lot of dust.

m

[rhtrades]

Thanks M.  What thickness core did you use? 

[msteinkampf]

This is from my deck rebuild thread, on which you have previously posted:

Although it’s hard to accurately measure the thickness of the old core material due to the water damage, it looks like it was nominal ¾-inch plywood, or about 23/32-inch thick.

I have much more detail about cutting and repairing the deck there: https://classicaquasport.com/smf/index.php?topic=16118.0

M

[rhtrades]

Thanks alot M!

[rhtrades]

believe it or not, i am having to replace the deck again.  The access hatch i put in a couple years back was not watertight and has caused  problems.  I am probably going to go with coosa this time.   I used a multi tool to cut into the deck last time around, but it took a long time and went thru alot blades, hence wondering if there is a better tool to use to cut fiberglass...