Why is the rock bleeding?

Bolt products bolt with ghastly Hilti RE-500 glue and inset showing the faded color two weeks after.

Don’t worry the mood slime from Ghostbusters 2 is not oozing out of your favorite crag! That very noticeable substance is a new type of glue being trialed for bolt replacement work; this new glue is the Hilti RE-500 epoxy. Thankfully, the very ugly color will eventually fade down to a more natural taupe color after a couple seasons of exposure to ultraviolet radiation. One important detail to note with this new epoxy is that the time it takes to “dry” (we use the word cure with epoxies). The cure time may reach beyond 48 hours depending on the ambient temperature. It is important to heed any signage at the crag regarding curing bolts. This is for your safety and the safety of future climbers.

Previously two different kinds of glue (modified epoxy acrylate and vinylester) have been used which match our natural rock color more closely. The reason to trial a different type of glue is to switch to a glue that is internationally regarded, has the longest possible service life, and is stronger than our previous types of glue (though both previous types are strong enough to meet or exceed UIAA requirements).

There are no specific UIAA standards for glue. All that exists are the UIAA 123 standards for fixed anchors. This leaves it up to the bolt manufacturer to figure out what glue to use in order to be “certified”. An example is Titan Climbing’s Eterna bolt which has only been tested with a regionally available epoxy or the Hilti RE-500 as the regional epoxy is not able to be shipped internationally (Titan is based in the U.K.). While a different type of glue will likely work with the Eterna bolt, the bolt’s installation won’t be certified. In the U.S. climbers mainly are using Hilti RE-500, Powers AC-100+, and ITW Redhead A7 for glue-in bolts. The last two are not well-known outside of North America and many companies are not willing to be evaluate them as substitutes.

Example signage regarding curing bolts.
Example signage regarding curing bolts.

For what it is worth, the bolts being used for replacement work supplied by Bolt Products are designed to be used with any type of adhesive. They’ve tested with the cheapest hardware store adhesives they could and still found their bolts met the UIAA’s 25kN standards. This is due largely to the helical twist design of their bolt which provides a sizable mechanical keying that secures the bolt.

While it’s still too early to tell if we will permanently be switching to the Hilti epoxy, you can expect to run into it at one point if you frequent the Bolton Valley area crags. As well you can expect a more substantial outreach to the local climbing community to communicate upcoming work on routes that will be effectively off-limits due to this slow-cure epoxy.

2 thoughts on “Why is the rock bleeding?

    1. Hi Dexter,
      A good idea but in practice working with spray paint at the cliff isn’t easy. You need to basically make a jig that fits around the bolt and limits the amount of rock that gets accidentally spray-painted. It’s also hard to make it look like someone didn’t just run up there with a can of spray paint and go at it. There is also a question of whether the spray paint will adhere to the epoxy and then there is the additional argument of using yet another chemical. Nail polish might be better as you could “target” the application better.

      I think all of that is moot though as the color fades faster than I was led to believe. I updated this post with a photo showing that after a couple weeks the color mutes down considerably. Based on what I’ve seen in Québec this will continue to fade till it is almost beige/taupe. We got one pack of 500SD and two packs of the V3 revision (used at the Bog Wall) which seems to be a more vibrant red color and seems to take longer for that color to mute out. That could also be because that crag gets less sun exposure. We’ll see what happens there in the next few weeks/months.

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