Graphite coating

Laszlo...

I'm getting ready to do a graphite coating on the bottom of my Auk. Joey says you add some silica to the mix and it makes it ultra strong. Can you share your secret formula?

Thanks,

Dan


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RE: Graphite coating

Dan,

It's not a secret. My current formula is on my WD12 build page. These days I use a 50-50 mix by volume of graphite and epoxy. Back in the day I used to decrease the graphite and put in 10-15% cab-o-sil. I stoppped doing that because I found that for my conditions (mud with occasional oyster shells, waterlogged wood, gravel and rarely a concrete ramp) that slipperiness worked better than hardness.

One thing you could try is to use a layer with 15% cab-o-sil, 35% graphite covered by a layer of 50-50 graphite epoxy. That way you'd have the soft & slippery to handle the initial contact and if that's not enough, the cab-o-sil layer will back you up.

So hope this helps,

Laszlo

 

RE: Graphite coating

Here's the result...

Note the dynel rub strips. I'll need to fill the weave on them a bit more. What happens when I sand this stuff? There are a few spots that might need some touch up.

Dan

RE: Graphite coating

Looks good. When you sand it goes to a flat Grey/black finish.

And you make black dust!

 

David

RE: Graphite coating

Do you do the graphite coating after the 3 or so coats of epoxy to fill the weave?

 

Lance

RE: Graphite coating

Lance,

This was the 3rd coat for the bottom. Everything else was 3rd coated as normal.

Dan

RE: Graphite coating

Looks good Dan. Davi'd's right about the dust, though. Don't sand it indoors unless you like the coal mine look. In fact, wet sanding would be the perfect option. Or just leave it unsanded.

Laszlo

 

RE: Graphite coating

Too late...

I gave it a quick sanding later night with 120grit on my ROS hooked to me vac. Minimal dust. Then I gave it a very light coat with a roller tipping out with a foam brush just to touch up a few spots and fill the weave of the dynel a little more. Done!

 A few more bits to glue on then on to the sanding and varnishing of the rest of the boat

Dan

RE: Graphite coating

Dan and Laz

How much graphite powder do I need to order for the bottom of my woodduck 10( I'll probably re-coat the bottom of my painted WD12 with graphite /epoxy also).

Thanks

Rod

RE: Graphite coating

I got the quart can and it seems like enough for 4 boats

Dan

RE: Graphite coating

Thanks Dan

Rod

RE: Graphite coating

Dan

CLC sells a can of graphite that says 12 ounces, it looks like a quart size can , is that the one to get?

Thanks

Rod

RE: Graphite coating

Yup

RE: Graphite coating

Dan;s right. I bought a pound years back and have done 4 1/2 boats with it (including the occasional touchup).

Laszlo

 

RE: Graphite coating

Laszlow,

I think we are all curious about the 1/2 boat with graphite bottom.

Paul

RE: Graphite coating

RE: Graphite coating

Well said.

RE: Graphite coating

Just took my CH16 down the Hootch here in Atl... I really think I need this graphite coating.. and the Dynel.  The rocks which were submerged a few inches really did a number on the hull :( I was hoping it would have held up a bit better then that...:(

Hit a couple small shoals/rapids and all went fine til the last one, boat came around and I couldnt get it straight in time.. oh well.

Do i just need to sand off the varnish on my CH16 bottom and apply the Graphite? how many coats? I am guessing the dynel goes on top of this?..

 

thanks in advance...

 

Frank

 

RE: Graphite coating

I put dynel and graphite on the ends of my Merganser after an encounter with a concrete launching ramp scraped it down to the cloth. After two active seasons of use, and more scrapes on the same ramp, the bottom is scratched up a bit but the graphite is still smooth and shiny. Be forewarned, though, that the dynel absorbs a lot more epoxy than the fiberglass does. -Wes

RE: Graphite coating

Frank,

You doneed to sand off the varnish, otherwise the graphite/epoxy won't stick. The number of coats and recipes were discussed at the beginning of the thread.

Laszlo

 

 

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