Repairing a Core Shot with Expoxy/Graphite Powder

[reganized]

I have done a few repairs using West Systems Epoxy and West Systems Graphite powder. I noticed that when finished, the repair is a little low to the base.

Does anyone reccomend doing the repair a little high on the base and stone grinding the repair down.

It seems like the best idea to me. With the graphite in the Epoxy it becomes pretty smooth. Works for racing boats, why not skis! The system is fully sandable and meant to be worked on after it sets.

[karpiel]

Works for racing boats, why not skis! The system is fully sandable and meant to be worked on after it sets.

Answered your own question. Why not just use p-tex though? I can't imagine the epoxy holds wax.

[reganized]

Epoxy works much better than P Tex when it comes to major repairs when there is no base material left to adhere the P Tex to. I had a 1 1/2 inch by 1inch hole caused by a broken gate back in the day. Ski was brand new. first day on snow.

The repair held perfect and when I sold them years later, you could barely see the repair, i did disclose it though. I had help with the repair but same process I use today. Just looking to fine tune my repairs.

Skiing on low snow levels in the New England woods is not good for skis!

The Graphite Powder will offer some of the properties of wax/base material while leaving me with a permanent repair.

[El Chupacabra]

I thought the recommended fix for big core shots is to use enough epoxy to fill the hole roughly halfway. Then while the epoxy is wet, sprinkle little bits of ptex (cheese grater some pieces) into the epoxy. Let epoxy cure. Then ptex the rest of the repair into place.

The little bits of ptex in the epoxy give the second stage of the repair something to hold onto.

[F.D.V.]

This is the method that I have used on my deep core shots and have not had a problem yet.

Cant imagine filling the hole 100% with epoxy!

I thought the recommended fix for big core shots is to use enough epoxy to fill the hole roughly halfway. Then while the epoxy is wet, sprinkle little bits of ptex (cheese grater some pieces) into the epoxy. Let epoxy cure. Then ptex the rest of the repair into place.

The little bits of ptex in the epoxy give the second stage of the repair something to hold onto.

[vanisle]

the proper way to fix large coreshots,especially near the edges is to patch with a piece of base material,not really any more work involved than what has been suggested here.

[karpiel]

I thought the recommended fix for big core shots is to use enough epoxy to fill the hole roughly halfway. Then while the epoxy is wet, sprinkle little bits of ptex (cheese grater some pieces) into the epoxy. Let epoxy cure. Then ptex the rest of the repair into place.

The little bits of ptex in the epoxy give the second stage of the repair something to hold onto.

Sure as hell makes more sense to me.

[Gunder]

FYI in that application graphite powder is not doing jack shit for you.

If you nee to add strength, steal wool is a much better choice.

"The Graphite Powder will offer some of the properties of wax/base material while leaving me with a permanent repair."

Not true as the graphite is fully encased in the epoxy matrix.

[XXX-er]

http://tognar.com/base_repairs_tips_ski_snowboard.html

anybody used that copolymer repair material they mention ?

[reganized]

Haven't had much luck with the 50/50. I'll try the cheese grater ptex on a pair of rock skis to test it out. I used to carve a grid pattern into the tacky epoxy and then ptex over once cured. The P Tex never seemed to hold though.

The dried epoxy with the graphite powder has a much different feel to it than standard epoxy.

I would agree with the West System description of the product. Not saying it's perfect but a hell of a lot better than epoxy or doing the p tex all the time.

423 graphite powder a fine black powder that can be mixed with epoxy to produce a low-friction exterior coating with increased scuff resistance and durability. Commonly used as a coating on rudders and centerboard, on the bottoms of racing craft that are dry sailed.

[Gunder]

Haven't had much luck with the 50/50. I'll try the cheese grater ptex on a pair of rock skis to test it out. I used to carve a grid pattern into the tacky epoxy and then ptex over once cured. The P Tex never seemed to hold though.

The dried epoxy with the graphite powder has a much different feel to it than standard epoxy.

I would agree with the West System description of the product. Not saying it's perfect but a hell of a lot better than epoxy or doing the p tex all the time.

423 graphite powder a fine black powder that can be mixed with epoxy to produce a low-friction exterior coating with increased scuff resistance and durability. Commonly used as a coating on rudders and centerboard, on the bottoms of racing craft that are dry sailed.

It still wont make a difference. There is no way you will notice the increased friction from a base repair that is under a few square inches. If it is bigger than that then you need to do a proper base repair with a new piece of ptex.

Now here is a few things.

Ptex candles suck. Burning PTEX to drip it into a repair is DEGRADING the PTEX aka HDPE or UHMWPE.

For a Ptex-ptex bond only, then if the area is properly cleaned, melting ptex aka a base weld is the best option. Remeber you need to get the base as hot or almost as hot as the material you are melting into it for the best bond.

Finally P-tex is specially treated at the factor to bound to the skis lower composite layer. Generally this is done with a corrona treament, and the material is sand to increase the surface are a for a better bond. Epoxy is the only reliable method of bonding ptex to the ski. But inorder for it to work the ptex must be properly prepped.

[1wsguy]

I had a 1 1/2 inch by 1inch hole caused by a broken gate back in the day. first day on snow.

Skiing on low snow levels in the New England woods is not good for skis!

Ski racing in the woods? ........That could be fun!!!

[skifishbum]

Toyko used to make a powder that you filled the coreshot with and then put on this cellephane sheet over and heated w/ an iron. tough to get to the right temp w/out bubbling the base but it worked surprisingly good esp on thin bases.Preheat with a liester (hot air gun) and the polyman
has been working well for me but thats a +$2,000 investment. Gunders right though what ever method you use a clean and preheated work area yeilds better results.

[reganized]

I've got the cleaning/prep done right and am working with a heated base. I don't own a P tex gun, would be interested if one comes around the gear swap for under $100.

[likwid]

It seems like the best idea to me. With the graphite in the Epoxy it becomes pretty smooth. Works for racing boats, why not skis! The system is fully sandable and meant to be worked on after it sets.

As others said, half fill, ptex over the top.
Using 423 isn't going to help you any.

And to have done it right you'd have to overfill and sand then wetsand.

Also by doing a full fill you're creating a dead spot in the ski.

If it were better than ptex then everyone would be epoxying then sanding their bases. The drag coefficient between snow and water is different.

I fucking hate wet sanding west with graphite powder.

[El Chupacabra]

Toyko used to make a powder that you filled the coreshot with ...

I've seen that stuff, I think in the Tognar catalog, but haven't tried it.

I get my best results on base repairs by exacto-knife cutting out the rough area, heating the general area of the repair with a heat gun, and -- while the ski surface is warm -- just melting in ptex candles with the tip of a cheap (low temp) soldering iron. Let it cure/dry overnight, then level the repair with a surform tool:

http://www.sears.com/shc/s/p_10153_1...0070921x00003a

The harder ptex candles work better for this, not the light-and-drip ones.

I've never had much success with the light-and-drip candles. The repairs don't stick to the ski base well and tend to rip out when I try to level the base. Maybe those drip candles are just for superficial/cosmetic scratches; I don't bother fixing those.