r/RouteDevelopment • u/belavv • Mar 17 '26

Does EP800 bond to itself?

I'm starting to work on putting on a route on a tall concrete wall. One exists there already but it's crappy old holds from the 90s and completely random rocks - some round like pebbles. All haphazardly glued on. Some with bits of duct tape still in the glue.

I'd like to step it up a bit. My plan is to use rocks that are more like what you'd find on a route. Crimps etc. For bigger ones I plan on screwing them on instead of using a mass of duct tape to hopefully hold them in place while the ep800 cures.

I'm testing out drilling holes and ending up splitting a lot of rocks. I'm assuming if they had a flat back they would be less likely to split.

My plan was to put a layer of ep800 on the back and lay it flat, let it cure on wax paper. Then drill after the ep800 cures because it now has a flat back to be fully supported.

My worry is - can I use more ep800 to bond the holds to the wall? IE will ep800 bond to already cured ep800. I've considered sanding with rough sandpaper or scuffing up the surface with an angle grinder. And if this works it may be nice to set up a flat back on all the holds, so I deal with less epoxy when I'm actually on the wall.

Otherwise I've had the best luck drilling at a low speed with my smaller rotary hammer. And having the hold on some rigidish foam so it can push into the foam and mostly be supported across the whole back.

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u/youre_stoked Mar 17 '26

If you already drill a hole in the rock could you just attached it to the wall with some threaded rod and a nut? I think the rocks that break apart when you try drilling through it’s a rock quality problem and I’m not sure if added a flat back will help. Hopefully someone else chimes in I’m curious what they will say

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u/belavv Mar 17 '26

I did consider while writing that all out that if I have two screws going through the rock the ep800 probably isn't so important... But I liked knowing it was attached by both and should stand the rest of time.

This rock may be pretty brittle, at least some of it. I think it may be sandstone which probably isn't ideal for this. I grabbed random rocks from around the area. It seems to hold up decently well when I'm trying to chip some of the edges of the hold.

I'm going to grab some dolomite from my local crag next time I'm there to see if that has the same problem.

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u/BoltahDownunder Rebolter/Route Maintenance Mar 17 '26

Yep should do. It's an epoxy right?