backing plates in the wild arrived: G10 stock

[Boulter]

Hi:

Received my 1/4 and 1/2 inch G10 material last week. This stuff looks tough as nails.

I was going to use 1/2 inch everywhere, but now I think I'll use 1/4 inch under stanchion bases and the like and save the 1/2 inch for the high load stuff like cleats and chain plates. Fender washers will be used as well.

Pretty well everything is loose as is, as the under side fiberglass is about 1/16 inch thick, so all the mounting hardware has dimpled the glass and compressed the core. I am drilling out and potting each hole with epoxy to isolate the core from future leaks.

I plan to cut this stuff with a 7 or 8 inch carbide tipped blade on the table saw. That will get the surface speed down a bit as opposed to using a regular 10 inch blade. Will bevel the edges at 45 degrees to avoid hard spots.

Now I just need some sun to dry out the core and allow me to work without freezing to death. Maybe next week ...

I don't think using G10 is that novel, but if anyone needs a report on how it goes, let me know.

Cheers

Boulter

[s/v Jedi]

Where did you buy it and what did it cost?

[roverhi]

I'd use a table and chop saw with carbide to cut some 12x12x3/8" pieces out of larger stock Found it easier and cheaper to use a saber saw with carbide grit blades.. Reciprocating Saw Blades: Carbide Grit Edge Blades | DEWALT Tools

Cut a couple of pieces of 12"x12" x3/8" FRP pieces with the carbide blade on my table and chop saw. Ruined the blaldes cutting 3 pieces. Way cheaper to buy saber saw blades that 10" table saw blades. The saber saw blades seem to last longer as well.

[MarkSF]

Like any fibreglass material, adequate protection is important when machine cutting it - safety glasses, dust mask, ideally overalls too.

[jcapo]

Originally Posted by s/v Jedi

Where did you buy it and what did it cost?

mcmaster.com has G10 but its a bit pricey. I use this stuff which is a very similar material and works for backing plates just fine.

Order Plastic GPO-3 Plate in Small Quantities at OnlineMetals.com

[s/v Jedi]

Originally Posted by jcapo

mcmaster.com has G10 but its a bit pricey. I use this stuff which is a very similar material and works for backing plates just fine.

Order Plastic GPO-3 Plate in Small Quantities at OnlineMetals.com

G10 is a bit cheaper on Amazon (as good as half the price for some sizes): Phenolic Solid Sheet, Natural, Inch, Standard Tolerance, Meets MIL-I-24768/27/GEE Specifications: Amazon.com: Industrial & Scientific

thanks,
Nick.

[minaret]

I just make my own flat stock. Cranked out a 4'x8' sheet of 1/2" today. Cost less than $100 in materials, very easy to do. I can't see paying for G10 unless you really need something that ridiculously strong.

[s/v Jedi]

Originally Posted by minaret

I just make my own flat stock. Cranked out a 4'x8' sheet of 1/2" today. Cost less than $100 in materials, very easy to do. I can't see paying for G10 unless you really need something that ridiculously strong.

In epoxy? Do you use cloth - roving - cloth layering? And then press with a weight? I know it is good when you do it regularly so that you can develop a system and re-use means but for most of us it is done very little if at all and the bilges are full with stuff already so we can't keep the tables/press etc.

Still, I would be willing to make smaller pieces when I can't get anything else...

[Lojanica]

Diamond tipped blades work well. All blades can be had with diamonds glued/embedded. Sawzall, bandsaw, circular saws, etc.

G10 will eat into other material not as strong. High density G10 is not the same as the other inferior stuff. It doesn't bond that great but is great as a wood/G10 sandwich and as you said backing plates. Thin epoxy treated ply then 1/4" G10 works great if your glass is thin otherwise the G10 will dig into the thin glass and core. You can make a larger wood piece then a smaller G10 piece as backers then crank the hell out of it and occasionally tighten even more. If you have solid glass or a stiff heavy core than straight G10 is fine bit take the sharp edge off the G10 so it doesn't cut into the adjacent material. You almost don't need fender washers unless it's a high load item then yeah G10 with fender washers between the nuts and G10 is better.

Don't throw the G10 sawdust away 'cause you can sprinkle it on your cornflakes and also if you plant a small piece in fertile soilyou can come back and harvest it in a few years.

[estarzinger]

By the way, G10 hold threads quite well. I tap the holes when I use it as backing plate material. That makes things even more leak proof and spreads the loads even better. It is tough stuff and does dull the taps pretty quickly though.

[foggysail]

I have used G10 while in engineering. That is one tough stuff to work with. I avoid using it as much as possible. I could not even get epoxy to stick onto it. It is dangerous to cut, ruins tools and there are better things to use. For backup plates I have used both plywood and 1/4" aluminum. G10 is super strong, just a real bitch to work with and not everybody has diamond saws.

[Lojanica]

Originally Posted by foggysail

I have used G10 while in engineering. That is one tough stuff to work with. I avoid using it as much as possible. I could not even get epoxy to stick onto it. It is dangerous to cut, ruins tools and there are better things to use. For backup plates I have used both plywood and 1/4" aluminum. G10 is super strong, just a real bitch to work with and not everybody has diamond saws.

All true. The one advantage to G10 is it doesn't deform. It flexes and returns to its shape. Metals will bend during repeated flexing cycles and eventually deform although titanium is less likely to deform. So that's where G10 excels. If you're backing a part like a traveler or vang or anything that will have a lot of flex, stress and movement the G10 excels. Using G10 with another substrate like wood or metal can help as they will complement each other. For instance the G10 will keep the metal from deforming or the wood will dampen the harsh characteristics of the G10. But as stated the stuff is an absolute bitch to work with and unless needed is better left to those areas where it's truly needed or your gonna swear and wear.....

[Boulter]

Originally Posted by s/v Jedi

Where did you buy it and what did it cost?

Jamestown Distributors, about $210 for 2x3 feet 1/2 inch. See JD site for other sizes. Only other place I found it (don't recall exactly where) was substantially more, about $300. Plus 35% to get it here. It seems UPS accrues most of the savings importing stuff to Canada. The cruising on $500 thread would be cruising on $750 in Canada.

Thanks to others for their comments on machining and safety. I have about a half dozen 8 inch carbide blades picked up at a garage sale or somewhere, so I'll see how they make out before investigating anything more robust. This might provide an opportunity to try out my diamond hones. This stuff isn't coming anywhere near my 10 inch woodworking blades!

Boulter

[Saltyhog]

The stuff is difficult to work with. To epoxy, I find that if you deglaze the surface with a coarse disk, thickened epoxy adheres very well. I've cut it with carbide blades and I've used hole saws with it. I use it for thru-hull backing blocks and I thread the mounting holes with a tap (per Maine Sail). Really works well. I sure wouldn't build a boat from it, but for some applications, it's the right material for the job.