Cutitng Fiberglass

[Fire19]

I am ready to install a larger Hot Water heater in my 5th Wheel I have to open the hole in the Fiberglass by 4" on top and 4" on one side. What is the best way to cut the fiberglass without it chipping and cracking. This is on a 2002 Gulfstream Seahawk. Thanks

[hypoxia]

seaeagle2 wrote:
When you're done, take a cool shower, (a hot one will open pores and drive the fiberglass dust into your skin)

I wish I had known that before!

I use the pizza cutter also. Never heard it called that but I like it!

[seaeagle2]

You're going to want a good dust mask, googles, and a disposable tyvek suit. When you're done, take a cool shower, (a hot one will open pores and drive the fiberglass dust into your skin), cutting fiberglass is a nasty itchy task. I replaced a transom on a boat and pretty much used every power and hand cutting device known to mankind. The die grinder with disk was the best ( other guy called it a pizza cutter).

[Chris_Bryant]

Another vote for the oscillating cutter, go through that like butter. At the factory it would have been a router with carbide bit.

[Jack_Spratt]

Abrasive grit blade in a reciprocating saw

[ppine]

I used to build fiberglass sail boats in WA state. One of the best tools is an air powered pizza cutter. A little round saw with 3 inch blade.

[2manytoyz]

As already mentioned, an oscillating cutter. I used a cheap one from Harbor Freight to cut a fiberglass cover I made for an airpack (for work).





Link to the oscillating cutter: https://www.harborfreight.com/variable-speed-oscillating-multi-tool-63113.html

The tool itself works great, but I would suggest upgrading the blades if you plan on using it for more than a job or two. Here are the blades I'm now using: https://amzn.to/2DNsbge

[Terryallan]

LarryJM wrote:
Dremel either an abrasive fiber cut off wheel or a dremel mighty max with the 1/2 round cutoff blade. I would test first on a line inside where your final cut will be for practice and get some experience.

Larry

Agree. Something without teeth would be best.

[LarryJM]

Dremel either an abrasive fiber cut off wheel or a dremel mighty max with the 1/2 round cutoff blade. I would test first on a line inside where your final cut will be for practice and get some experience.

Larry

[Z-Peller]

Cut so blade teeth are going down thru gel coat side of material..scroll saw teeth will pull up thu material and chip gel coat. Put masking tape on gel coat side and cut with fine tooth saw pushing. Don't drag on the backstroke. Drill starter hole inboard of cut line if needed..

[beemerphile1]

Oscillating saw, pick one up at Harbor Freight cheap.

[RedRollingRoadb]

Run some painters tape then cut through it. I will help reduce the possibility of chipping.

Got clearance? No frame or any thing in way?

[navegator]

Use carbide blades on a scrollsaw unit, cut a bit smaller and then use a file to finish the cut, go slow and let the blade do the work if you push too hard you will chip the edges, going slow makes a cut that needs very little dressing.

navegator