Hurricane Spade Grip Alloy?

Thought I’d share photos of the first step in the restoration of my AH2040 grip. Next step is to fill in, and sand to match the original profile.

I’ll send you a PM with pics.

Hi Ron,

Any chance of seeing some photos of your project?

Spade grips are hollow also with a steel tube inserted internally for the pneumatics I thought.For resin parts 3D printing is a good alternative and also for casting masters.

In the queue

Hi Ed,
Any luck with the CCF Hurricane spar?

Not yet, I am building up a group of specimens to justify hiring XRF for a day to quickly confirm the chemistry, will report duly…

Hey Ron,

How goes it?

I had the same problem with my grip, my cable guide is actaully made from a bit of cast Spitfire. I found it was very close to the original shape just has to cut the front slot, it was then shaped to fit, bonded with fibreglass resin and shaped with the same resin and filler to blend in, if you hit it with a hammer it may break off but I’m not planning on doing that:) Must send you some pics.

Hi Ed,

I thought that I had answered about the Wirraway starter switch. Perhaps not. It’s not the switch I’m looking for unfortunately.

Using an epoxy is a great idea. Had thought about the machine a slot and using hidden bolts but the epoxy will be much easier.

Any luck with the CCF Hurricane spar?

Cheers,

Ron

Forging ahead

I have a CCF made AH2040 spade grip from a Hurricane where the brake cable guide has been filed off so that the grip could be used in a Harvard. I want to restore the cable guide. My question is this… what alloy material was used to cast these grips? I want to use the same material.

Ron,
Forgive me for half hijacking your post but I also want someone to confirm or deny that these spade grips were originally forgings rather than castings. I would love to get a broken grip and slice it across its face to try and find a circular grain pattern. Anybody got a chunk of useless grip ? I am more familiar with the mid 30’s grips made by BSA, which are exquisitely finished where the metalwork shows. My hunch is that this critical component would not have been trusted to a relatively thin section casting used as the lever point between control surfaces, certainly in recovering from a dive. I wince at the cast reproductions that you see from time to time, though understand that this is an accessible pathway to a reproduction.

In terms of metallurgy I don’t know, but handheld XRF will be able to give basic chemistry that can be compared to various DTD and BS specs to provide a definitive answer. My gut feel would be to machine up the lug using readily available material and then machine a slot in your spade grip, and use an epoxy to bond both parts together. It’s admissible practice in Museum conservation for static purposes. If you weld dissimilar alloys together to form a machinable tag it introduces all sorts of possibilities. Even if you know the original metallurgy and match it, seventy year old alloy may have absorbed all sorts of environmental chemicals that frustrate the process by bubbling gases through your weld pool, and you only have one shot at it.

Folk seem to use an original spade grip as a pattern for sand casting of reproductions. Nothing wrong with that for static. It will shrink a few percent and you would have to use putty to fill the surface porosity to get anywhere near the original finish.

To machine out a forging pattern does not seem excessively expensive, as it is a fairly uncomplicated spoon shape that could be finished by machining and polishing. But that’s a hard way to reclaim a cable lug ! I have a NOS brake cable for you which I think is generic, or certainly you could work it up to something required. Did you see my email re Wirraway starter switch ?
Ed