Powers Glue Capsule's

Just looking for some people's experience with using the Powers Glue Capsules for glue in anchors. What are the pros/cons?

Never used the Powers ones but tested plenty of other companies (we make suitable bolts specially for capsules).

Hammer capsules are pretty rare (and a modern development) and expensive but have the advantage you just hammer the anchor straight in, I don´t know anyone who has used them for a climbing bolt.
The more normal type are vinlyester (Powers Chem Stud) and need the end of the anchor to be cut as a chisel point and be rotated as you hammer them in. Commercially you use a special tool on a hammer drill but climbers don´t bother, you just whack the bolt and twist it a few times, whack again and so on. Normal advice is to try to get 40 turns. Dead commonly used here in Europe for mountain routes.
In reality twisting can be quite difficult as the quartz crystals and broken glass grind their way into the rock so a short twisting bar in the bolt eye is useful.

You need to optimise the bolt length to the hole volume and the capsule, we make the bolts to allow 10% over on the capsule, more and it´s a bit of a mess to clean up. We do it by measurement, the capsule volumes are sometimes on the manufacturers info and the bolt volume you can measure by water displacement, then we test a few to make sure!

The resin is fairly runny so overhead installation is out.
They are generally quick to reach full strength, all the ones we´ve tested have reached full strength before we can install them in the tester.

Capsules always give the highest pull-out test results, better than epoxy as the liquid resin is literally ground into the surface of the bolt and the rock and vastly better than cartridge resins in sandstone.

The type in a plastic sachet should not be used unless you´ve tested them beforehand, they are generally spin-to-set and need to be rotated at high speed to cure as they contain no accelerator/hardener.

Jim, while on the epoxy subject, do you have an opinion on Redhead A7 . We have been using it for quite a while here in New England (Rumney especially) so far with no issues, but I have also read opinions stating that pure epoxy is better than acrylic for longevity. We like the A7 for work-ability, not much drip, cure time, color, texture and the fact that it can be used even if the rock is a little damp, plus it is pretty available and not over priced. I am wondering if possible alternatives are significantly better strength and longevity wise to make it worth switching.

Well not really, I´ve never used it and doubt it´s available in Europe anyway. Most vinylester/epoxyacrylates are plenty strong enough as that´s what nearly every manufacturer certifies with anyway. As long as the hole is sufficiently cleaned, the bolt has enough grooving and the rock is strong enough you can go for amazingly short embedment depth (like 3cm with vinylester) before glue failure is the problem, normally it´s either inadequate engagement in the bolt or dirty holes that cause the problems. Normal testing we expect around 50-60kN with an 8cm long bolt before the vinylester fails.
Longetivity- I´ve worked with epoxy for over 40 years in the marine industry and have seen no convincing evidence it lasts any better than the other resins in our application, vinylester gets the same 50 year recommendation as epoxy for the ETA certificate anyway.The 49 year old polyester boat lying in my garden seems to be holding up quite well!

Ok, very good! Thanks for the confirmation.

Jim Titt wrote:As long as the hole is sufficiently cleaned, the bolt has enough grooving and the rock is strong enough

M Sprague, I saw in some Swiss or French paper that glues like the A7 [acrylic] don't do well with lightly dimpled bolts like the Fixes. From what I remember the final pullout numbers were a hair below the UIAA minimum requirements. There was no issue using the glue with rebar, threaded rod, twist bolts or wave bolts.
For the Fixe bolts they recommended pure epoxy like the re500.

Interesting. I have gone more toward the wave style bolts lately, but still occasionally use countersunk Fixe glue-ins when I particularly want to lesson the visual impact. I like the finished look better than the wave bolts.

M Sprague wrote:Ok, very good! Thanks for the confirmation.

Indeed the epoxy is quite strong. For fun once I epoxied a 3/8" x 1" threaded grade 5 machine bolt into a piece of strong basalt and pull tested the bolt. I dont recall what the breaking strength was, but the head of the bolt broke off with the shaft still installed into the test sample. Granted, I used SET-22, which is the strongest epoxy Simpson makes, but still it was a fun demonstration.

rocknice2 wrote: M Sprague, I saw in some Swiss or French paper that glues like the A7 [acrylic] don't do well with lightly dimpled bolts like the Fixes. From what I remember the final pullout numbers were a hair below the UIAA minimum requirements. There was no issue using the glue with rebar, threaded rod, twist bolts or wave bolts. For the Fixe bolts they recommended pure epoxy like the re500.

You could thread the last 50% of the bolt. Personally, I would do that regardless of what epoxy I was using as those dimples are not the best option to add keying to the bolt. They might hold fine in a perfect scenario where you can place the epoxy in the hole standing on the ground. However, in the real world sometimes bubbles can form in the epoxy leaving a portion of the installed bolt exposed to air. The added threads would help in a situation like that.

That´s why if you do loads of testing you get a bit less involved in the whole idea of one resin is better than another, epoxy is stronger and you should only use product X etc. The bolt design and hole cleaning are the key factors to getting good results.
Using vinylester with an 8mm single-shaft bolt in a 10mm hole we can get the certification values with a 30mm long bolt (15kN axial, 25kN radial)as long as the rock is strong enough, in the concrete test blocks you need about 45mm. The standard requires 70mm embedded length and the industry standard is to make them 80mm just to cover installer incompetence and any resin deterioration.