Carbon and Fiber glass

[Terry Keeley]

Just not sure how well the carbon would glue as a bottom skin without the plywood. Still thinking about that....

Thanks Terry.... !!!

Hey Marty:

Good to here you messin' with the CF, you're gonna love it!

If you make small interior/exterior fillets the sheeting will never let go, here's a bulkhead:

Made a little tool but you could do it freehand:

 

[Terry Keeley]

Terry whats a good mold release to use and where canis i get it. Also do you use oval?

I use Partall wax and PVA, available at any decent supplier.

Not sure what you mean by "do you also use oval"?

 

[Lay26]

Don't know what I was thinking.

 

[Marty Davis]

Just not sure how well the carbon would glue as a bottom skin without the plywood. Still thinking about that....

Thanks Terry.... !!!

Hey Marty:

Good to here you messin' with the CF, you're gonna love it!

If you make small interior/exterior fillets the sheeting will never let go, here's a bulkhead:

Made a little tool but you could do it freehand:

Terry:

What is the foam core that you are using?

Without a vacuum bag system, I will always have a smooth side and a rough side. I will probably go with 1/32" ply for the bottom and the top skins. Don't think that I would like the rough side in the interior of the tub.

 

[Marty Davis]

Terry:

I can't find my invoice, but I think that you had me get the Plain Weave 3K PW 199GSM 50" at $29.95/yd.

Is that correct?

Thanks,

 

[tnrcboatracer]

I have a vacuum system that works very well. The best thing is to make a CF sandwich the way Terry does. You can also make the sandwich with a couple of plates and a bunch of clamps.

 

[Terry Keeley]

Terry:

What is the foam core that you are using?

Without a vacuum bag system, I will always have a smooth side and a rough side. I will probably go with 1/32" ply for the bottom and the top skins. Don't think that I would like the rough side in the interior of the tub.

It's 1/4" (6.35mm) Rhoacell 71 from CST:

http://www.cstsales....cell_71_IG.html

Kinda pricey but good stuff. Another option could be to slice up some Kledgecell or Divinycell with a table saw or even use balsa.

As Jon mentioned I think it would be stronger and lighter to do a cored layup all at once, ie: 2 layers CF, core, 2 layers CF and press it all together with weights or clamps. You could put waxed paper on top to get a good finish although mine is rough one side from the peel ply, I just sand it.

Terry:

I can't find my invoice, but I think that you had me get the Plain Weave 3K PW 199GSM 50" at $29.95/yd.

Is that correct?

Thanks,

That's a "standard" 6oz cloth, it'll work fine for almost anything. I generally like the 1K, 3oz cloth on the outside of layups as the pinholes are smaller but that's just me.

I have a vacuum system that works very well. The best thing is to make a CF sandwich the way Terry does. You can also make the sandwich with a couple of plates and a bunch of clamps.

Yup!

If you use the same weight of resin as cloth you will end up with a 50-50 layup which is ideal, clamp or weigh that down and it'll be every bit as good as if you used vacuum.

 

[Terry Keeley]

Were are all of you getting your knowledge from or did you learn from??? I would like to start something to get me more involved with this hobby and would like to learn how to use these products and the proces involved as they spark a interest in me!!!

Thanks, Kevin.....

Terry Keeley started me thinking while at the Internats. He suggested that I buy some 6oz woven Carbon Cloth and make some Carbon Plywood. I got a piece of glass 4' x 4' and waxed it and then put a layer of West System on the glass. Then the carbon cloth and an auto body squeege to scrape off all the excess West Epoxy. The sheet came out perfect and SUPER LIGHT. I will use it to build a new 20 boat using all the same methods, just use the .012" carbon plywood instead of birch plywood. Can't wait to see the weight savings and the strength too. Thinking of doing the same thing but bond a layer of 1/64" ply to a sheet to make it glue really well for the top and bottom of the center section. Or, I could just double the carbon layer. Just not sure how well the carbon would glue as a bottom skin without the plywood. Still thinking about that....

Thanks Terry.... !!!

Try squeezing the cloth somehow, clamps, weight, press etc, when squeezed the 6oz cloth ends up about 0.008" thick/ layer and has much better properties...

 

[wayne middlemiss]

Marty

Aaron and myself have been doing this for some time

we also tried to sandwich balsa but i think it soaks too much resin

next tub im going to try making the tub top and bottom skin 1 part

buy using an internal mould

Greg

not at all greg i done boats that way 20 years ago and did actually see the last boat hit concrete dock wot and only bust in half not crumble up. also i do use cedar as it comes out with good results to as core material. did you thin your epoxy down too much.

 

[John Beardslee]

Marty

Aaron and myself have been doing this for some time

we also tried to sandwich balsa but i think it soaks too much resin

next tub im going to try making the tub top and bottom skin 1 part

buy using an internal mould

Greg

not at all greg i done boats that way 20 years ago and did actually see the last boat hit concrete dock wot and only bust in half not crumble up. also i do use cedar as it comes out with good results to as core material. did you thin your epoxy down too much.

Greg,

The last two twins we built we used quarter sawn cedar all laticed out as the core. It's really quite stable and with laser cutters available would work good. Almost any material can work well actually because it's the thickness that gives you the seperation distance and that is where the strength and stability comes from.

John

 

[tnrcboatracer]

The pics of my vacuum pump system are in my gallery. The most important part is the tank and pressure switch. Any tupe of pump will work. I just use oil free because of the mess the A/C pumps make ith hte oil fumes. We don't need 29+" of vacuum, anyhow.

And as Terry said, I have sliced Klegecel on my tablesaw to make 3/16" and 1/4" cores. I also use Rohacel 1mm, 2mm, and 3mm core for cover panels and cowls. The core makes the cowls and covers self bouyant.

http://www.intlwater...lery&image=6084

http://www.intlwaters.com/index.php?app=gallery&image=6082

http://www.intlwaters.com/index.php?app=gallery&image=6083

 

[Marty Davis]

Were are all of you getting your knowledge from or did you learn from??? I would like to start something to get me more involved with this hobby and would like to learn how to use these products and the proces involved as they spark a interest in me!!!

Thanks, Kevin.....

Terry Keeley started me thinking while at the Internats. He suggested that I buy some 6oz woven Carbon Cloth and make some Carbon Plywood. I got a piece of glass 4' x 4' and waxed it and then put a layer of West System on the glass. Then the carbon cloth and an auto body squeege to scrape off all the excess West Epoxy. The sheet came out perfect and SUPER LIGHT. I will use it to build a new 20 boat using all the same methods, just use the .012" carbon plywood instead of birch plywood. Can't wait to see the weight savings and the strength too. Thinking of doing the same thing but bond a layer of 1/64" ply to a sheet to make it glue really well for the top and bottom of the center section. Or, I could just double the carbon layer. Just not sure how well the carbon would glue as a bottom skin without the plywood. Still thinking about that....

Thanks Terry.... !!!

Try squeezing the cloth somehow, clamps, weight, press etc, when squeezed the 6oz cloth ends up about 0.008" thick/ layer and has much better properties...

Terry:

How do you get a clean hole for the sponsom booms, etc? Seems that carbon tends to have threads when you try to cut the hole. Have you tried a Forstner Bit? That would be my first thing to try.

 

[Ron Jefferson]

I'm not sure about Carbon Fibre but a buddy put me on to these for boom and engine mount holes.

http://www.google.ca/imgres?imgurl=http://www.harborfreight.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/i/m/image_11761.jpg&imgrefurl=http://www.harborfreight.com/3-piece-titanium-nitride-coated-high-speed-steel-step-drills-91616.html&h=1200&w=1200&sz=133&tbnid=pJhcdA4Trr5ZQM:&tbnh=90&tbnw=90&prev=/search%3Fq%3Dstep%2Bdrill%2Bbits%26tbm%3Disch%26tbo%3Du&zoom=1&q=step+drill+bits&usg=__5vbQyYdGJxvbEe__IuzpLRfLWSY=&docid=JuoELccXtt1SDM&hl=en&sa=X&ei=QAkcUdm2IsK-yQHxlIGQCA&sqi=2&ved=0CGoQ9QEwBg&dur=605

 

[Terry Keeley]

Terry:

How do you get a clean hole for the sponsom booms, etc? Seems that carbon tends to have threads when you try to cut the hole. Have you tried a Forstner Bit? That would be my first thing to try.

Yup, forstner bit works as well as these "pilot point" bits:

http://www.dewalt.com/tool-parts/drilling-accessories-metal--wood-drilling-general-purpose-pilot-point-drill-bits-dw1909.aspx

 

[tnrcboatracer]

Marty, Carbon cloth does not fray so much. It can splinter if it is unidirectional material. You can put a scrim of 0,25oz glass cloth on the outside to reduce the spintering. The kevlar tracer threads in some carbon cloth will fuzz around the hole. As will any kevlar hybrid cloth, the only way to cut kevlar cleanly is with a waterjet machine.

If you want to make an SGX type tub that tapers at the front, you can vacuum bag to a curved caul sheet. This gives a stress free tub wall with the premade curve. I've also done that with radio box lids for the Crapshooter and UFO tubs. I make a curved sheet that matches the top of the hull exactly, and layup the box lid on this sheet.

 

[tnrcboatracer]

Here's the best way to drill CF for no fray. Lubricate with water. Best to use a high speed spindle and some sort of fixture. I.E. a drill press with a 60k rpm spindle. A pnuematic pencil grinder will work well.

http://www.ebay.com/itm/10-pc-DIAMOND-HOLE-Saw-Core-Bit-Set-1-8-Shank-Dremel-Rotary-Tool-100-Grit-/360500309373?pt=LH_DefaultDomain_0&hash=item53ef7e2d7d

 

[Marty Davis]

Here's the best wazy to drill CF for no fray. Lubricate with water. Best to use a high speed spindle and some sort of fixture. I.E. a drill press with a 60k rpm spindle. A pnuematic pencil grinder will work well.

http://www.ebay.com/...=item53ef7e2d7d

Jon:

Thanks, I ordered this set. Thanks for the tip!

 

[tnrcboatracer]

I forgot to mention to lubricate with plain water when drilling, and feed slowly. And make sure that the part is clamped down. It's not something that you want to do freehand. I used something like this when I was making satelite parts out west.

 

[Lennard Cuenco]

Marty/Terry et al:

is this carbon sheeting pliable enough for deck skin on a scale boat? (gentle curves to the chine), actually..nevermind, I'll do that with regular glass...great stuff tho..thx

im waxing my 5' x 3' sheet of glass now

Were are all of you getting your knowledge from or did you learn from??? I would like to start something to get me more involved with this hobby and would like to learn how to use these products and the proces involved as they spark a interest in me!!!

Thanks, Kevin.....

Terry Keeley started me thinking while at the Internats. He suggested that I buy some 6oz woven Carbon Cloth and make some Carbon Plywood. I got a piece of glass 4' x 4' and waxed it and then put a layer of West System on the glass. Then the carbon cloth and an auto body squeege to scrape off all the excess West Epoxy. The sheet came out perfect and SUPER LIGHT. I will use it to build a new 20 boat using all the same methods, just use the .012" carbon plywood instead of birch plywood. Can't wait to see the weight savings and the strength too. Thinking of doing the same thing but bond a layer of 1/64" ply to a sheet to make it glue really well for the top and bottom of the center section. Or, I could just double the carbon layer. Just not sure how well the carbon would glue as a bottom skin without the plywood. Still thinking about that....

Thanks Terry.... !!!

 

[tnrcboatracer]

It will not work well for compound curves. If you can make a mold of the compound surface, you can use the same process to make a pre curved skin. See my comments above on Crapshooter/UFO radio box lids and the SGX tub sides. It will work OK for a simple curve in 1 plane.