Ash bottoms for tough river?

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LookingGlass
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Ash bottoms for tough river?

Post by LookingGlass » Mon Jun 18, 2018 7:01 pm

Has anyone ever used ash for the football? I need a tough bottomed craft for my local river, and I’m planning to build something this winter and have it ready for glass in the spring; probably a Bobs Special or a ranger. Besides graphite on the bottom, and an extra layer of glass on the inner and outer hull, I’d like to make the bottom a little more bulletproof. I’m willing to sacrifice the weight since I won’t be portaging long distances, and I live on the river where it’ll primarily be used. I think ash strips on the bottom might be the ticket. Any thoughts?

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Patricks Dad
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Re: Ash bottoms for tough river?

Post by Patricks Dad » Mon Jun 18, 2018 7:58 pm

Don't do it. Strength of the hull is less driven by the core material (i.e., the wood) than what surrounds it. If you want to make it stronger, put more glass on BOTH sides of the hull. Consider using S-glass. Using heavier wood in the core won't make the hull much less likely to fail when impacted by a rock. And for scrapes, it's all in the outer surfaces anyway.

Save your Ash for gunwales and seat frames.
Randy Pfeifer
(847) 341-0618
Randy.Pfeifer1@gmail.com

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Jim Dodd
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Re: Ash bottoms for tough river?

Post by Jim Dodd » Mon Jun 18, 2018 8:40 pm

Got to agree with Randy.

Other options would be to add Kevlar, or Kevlar/Carbon.
Also Dynel, it's used as a barrier layer, against abrasion on the outside. I would substitute it for the extra outside glass layer. Coat it with Epoxy/Graphite.

A little research from fiberglass suppliers should help you !

Jim
Keep your paddle wet and your seat dry!

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Cruiser
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Re: Ash bottoms for tough river?

Post by Cruiser » Tue Jun 19, 2018 7:44 am

+1 on what Randy and Jim have suggested .... look at your bottom cloth materials, not the core.

Brian

LookingGlass
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Re: Ash bottoms for tough river?

Post by LookingGlass » Wed Jun 20, 2018 5:10 pm

Thank you all for the input. I'll research the different fiber options with a couple suppliers and return here when I have more questions. Great to be part of the forum BEFORE I build and make mistakes or get in over my head. Matt

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Jim Dodd
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Re: Ash bottoms for tough river?

Post by Jim Dodd » Thu Jun 21, 2018 10:57 am

Smart to Look Before you Leap !

Jim
Keep your paddle wet and your seat dry!

sedges
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Re: Ash bottoms for tough river?

Post by sedges » Thu Jun 21, 2018 3:54 pm

I have to agree with all of the above and add this. Kevlar inside, glass outside.

If you are adding layers to the bottom, inside or out, make sure you stagger the edges of the layers by several inches. Laminates often fail at an abrupt transition in stiffness. Spreading out that transition is always a good idea.

phmiller
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Re: Ash bottoms for tough river?

Post by phmiller » Sun Aug 19, 2018 6:13 pm

I've just read the post Ash Bottoms for Tough River. In my experience canoing on a river full of rocks,logs, sharp stones etc, a layer of epoxy and graphite mix will protect the bottom of your canoe. This is a very tough protective surface which takes a real hammering. Even after scraping over rocks in the water the results are only tiny scratch marks which are of no consequence. I think the smoother your hull the better, allowing your canoe to slip past most obstacles more easily. The fibre glass/wood composite construction is very strong, perfectly designed to handle most things. An extra layer of cloth might be the only thing you need to contemplate. I've had canoes thrashed in the surf at the beach and crashing against hidden logs or rocks in rivers and never come to grief ! Regards Patrick.

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Jim Dodd
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Re: Ash bottoms for tough river?

Post by Jim Dodd » Sun Aug 19, 2018 8:47 pm

Dynel is one of the highest regarded coverings for hull bottoms I've seen, or heard of.
It absorbs a lot of resin, but to counteract act this, I would add Graphite to the fill coats of a Dynel layered bottom.
RAKA handles this.
http://www.raka.com/Images/logos/banner ... parent.png

Here's a Youtube video that should help !
https://www.youtube.com/watch?v=WdaPecHY4VQ


Jim
Keep your paddle wet and your seat dry!

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cedarphile
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Re: Ash bottoms for tough river?

Post by cedarphile » Thu Nov 29, 2018 5:28 am

Keep in mind that graphite is black so absorbs lots on sunshine if left outside overturned on a rack. It has no inherent UV protection so will get very hot in direct sunlight. Epoxy softens at about 150 degrees so the black epoxy/graphite/silica will definitely soften in summer sunshine in southern states if stored outside.

To get around this, I mask off the hull at the 4" waterline and paint the graphite bottom with marine paint. Sure, the paint gets scratched, but I've never had a rock go through the black epoxy/graphic bottom underneath.You'll find the epoxy/graphite/silica coating is bulletproof, but because it's so hard, it can't be sanded. So get the coats on evenly with no runs.

Gary

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