Gluing brass or bronze into oak

[Woody2Shoes]

Is it? If the epoxy formed a "handle" through the hole in the brass ring, would it not be about the cross-sectional area of that piece of epoxy, and the strength of its attachment to the remainder of of epoxy?

I don't think that ordinary epoxy has particularly great shear strength, but is probably comparatively much stronger in compression - like cement really.

 

[MikeG.]

Ooooh, didn't know that.

But hang on, chemical anchors are all about resisting tension rather than compression.......

 

[Woody2Shoes]

Ooooh, didn't know that.

But hang on, chemical anchors are all about resisting tension rather than compression.......

I think it depends on the application - you mainly want good shear strength (from the fixing) and good pull-out resistance (from the surface area of the fixing in contact with the sa of the hole) - which is why larger diameters are soo much stronger in proportion.

 

[Jake]

Rather than relying on threads I think it is recommended for chemical anchor fixings to take an angle grinder cutting disc to the sides to create a series of notches.

 

[Woody2Shoes]

Rather than relying on threads I think it is recommended for chemical anchor fixings to take an angle grinder cutting disc to the sides to create a series of notches.

I think that it's less than ideal to take a grinder to it - especially if it's galvanized - bolts/anchors are fully threaded for a reason. Of course, the objective is the same in both cases.

 

[AndyT]

I wonder if you could exploit your use of metal to get an extra advantage?

If you do thread one or both ends and manage to hide a nut at one end which could be turned, then your stretchers could even be tightened up if it was ever necessary. The nut could be the sort with notches on the edge that can be punched around with the end of a screwdriver, as used on handrail connectors.

If you do as Mike suggests and cross drill for a transverse pin at the other end you won't need glue at all.

 

[Jake]

I think that it's less than ideal to take a grinder to it - especially if it's galvanized - bolts/anchors are fully threaded for a reason. Of course, the objective is the same in both cases.

Given it is destined to be encased in plastic resin the galvanising (should you be using mild steel) is kind of irrelevant. I didn't come up with this, it is gleaned knowledge from resin product sheets. Proper anchors are not [edit - "always"*] threaded, they are more like rebar in profile.

*Edited becase just checked a few of my leftovers and some are but some are just threaded.

 

[Woody2Shoes]

Given it is destined to be encased in plastic resin the galvanising (should you be using mild steel) is kind of irrelevant. I didn't come up with this, it is gleaned knowledge from resin product sheets. Proper anchors are not [edit - "always"*] threaded, they are more like rebar in profile.

*Edited becase just checked a few of my leftovers and some are but some are just threaded.

I notice that resin anchors for rock climbers often seem to be 'bobbly' rather than threaded, but for building they're nearly always threaded and galvanised - unless you're thinking of threaded inserts, when they're usually knurled. There's a general notion that it's better to have something manufactured under controlled conditions in a factory than on a building site by a geezer with an angle grinder!

 

[El Barto]

Thanks for the replies guys. Good shout @AndyT about being able to tighten them up if ever the need arises. Ideally though I'd like a cleaner solution than using bolts and did consider a small pin on each end... I'm leaning towards that at the moment.

 

[Deadeye]

i HAVE ONLY DONE THIS WITH PLAQUES AND HAD NO TROUBLE WITH USUAL 2 PART EPOXY

THAT'S GOOD TO KNOW.
Take your earplugs out. My throat's getting sore.

 

[Deadeye]

I notice that resin anchors for rock climbers often seem to be 'bobbly' rather than threaded, but for building they're nearly always threaded and galvanised - unless you're thinking of threaded inserts, when they're usually knurled. There's a general notion that it's better to have something manufactured under controlled conditions in a factory than on a building site by a geezer with an angle grinder!

Did someone say "rock climber"?

Yes, we generally don't use threaded. Firstly, the expectation is that the insert will not need to be removed. Secondly, the pull-test strength of plain anchors is easily sufficient to obviate the need for more expensive threads (and it can cost £'00s to equip a route).

The second-most important concern for climbers is strength. Lots of bolt styles (expansion, resin, loop) are fine, *provided* that they are well placed - which is the most important concern. "Well placed" particularly with regard to the rock (not friable or part of a larger unstable structure) and also cleaning well after drilling to enable epoxy to bond well. Fatalities have resulted from poor cleaning of drilled holes before glueing.

Generally overspecifying is a low premium for the issues it avoids.

 

[Jake]

I notice that resin anchors for rock climbers often seem to be 'bobbly' rather than threaded, but for building they're nearly always threaded and galvanised - unless you're thinking of threaded inserts, when they're usually knurled. There's a general notion that it's better to have something manufactured under controlled conditions in a factory than on a building site by a geezer with an angle grinder!

Yes, the ones I have seem to be special high bond ones. Yes obviously, but the guidance I recall was about sub-optimal use of studding rather than a purpose made fixing in an "if you have to" way. I can't find it, but it is possible I was mis-remembering advice to cut the end obliquely to help stop rotation.