Grip materials

[the reluctant fencer]

Originally Posted by migopod

I'm curious about the welding properties of grip aluminum. When you say that it welds poorly, does it do that thing where little pockets of impurity float up and leave you with
really porous welds, or is it just not particularly fluid during welding?

Well the grip aluminum is cast out of very impure aluminum. I am guessing it is straight from a scrap yard and melted down to be re-poured.
It is very hard to get the weld pool (for TIG) to move at all. Even prodding the pool with the filler metal it was hard to move.
I am pretty sure if you had a MIG setup for aluminum it would be a lot easier to join the pieces and then finish over it with TIG and then final sanding and painting or polishing.
Also when I finished welding there was all sorts of scum that floated out of the grip aluminum and was on top of the welds.

[Pescados666]

That reminds me...
Picture 1
Picture 2

And it in relation to a chicken
Picture 3

[migopod]

Is that an aluminum foil visconti?

i'm so making one out of ground beef... mark my words.

[magic_moose]

Originally Posted by migopod

I've had a lot of success just using files and sandpaper rather than heat with aluminum. Die grinders and dremmel tools work nicely too.

I'll vote with this. Every new grip I get I go over well with files and wet/dry sandpaper until it is just right for my hand. Otherwise, I tend to get very sore fingers and blisters.

[Pescados666]

Originally Posted by migopod

Is that an aluminum foil visconti?

i'm so making one out of ground beef... mark my words.

Yup. I'd make a few more improvements to it if I had a welder and knew how to weld... I could use lead fishing weights and pound them into what I want and tape them together, but that seems too ghetto.

[Nolano]

If I can get my hands on a spare grip, I'll give the welding a shot. I'm a professional welder, although I work in steel mostly, not aluminum. I'd like to try it.

[Pescados666]

Originally Posted by Nolano

If I can get my hands on a spare grip, I'll give the welding a shot. I'm a professional welder, although I work in steel mostly, not aluminum. I'd like to try it.

I was thinking of a triangular support for the palm of your hand. Something that fits better. You know what I mean?

[the reluctant fencer]

Originally Posted by Nolano

If I can get my hands on a spare grip, I'll give the welding a shot. I'm a professional welder, although I work in steel mostly, not aluminum. I'd like to try it.

Good to see another welder on here!
The thing is that when welding on the grip it needs to get up to temp before a weld pool will really form. Either you can bake it to as hot as possible before welding or just let the arc heat the grip. Once it gets up to temp it welds VERY quickly.
It also helps to make a jig to hold the pieces since they will be VERY hot and you can't position them with gloved hands. (fried some heavy duty MIG gloves on my first grip...LOL)

Pescados,
THIS is what I did to support the lower part of my hand.

Welding a triangle of aluminum sheet to the thick cast grip would be VERY difficult to do. The sheet would probably melt away before a weld pool forms on the grip material.

[migopod]

Originally Posted by the reluctant fencer

....
Welding a triangle of aluminum sheet to the thick cast grip would be VERY difficult to do. The sheet would probably melt away before a weld pool forms on the grip material.

Back in the day i used to repair boat propellers. Aluminum props tend to lose big chunks of their blades when they hit solid objects or wear down when they are consistently run through sand or gravel. The method that we used was to reshape the blade using cast iron blocks and hammers and then to tig a bead around the broken off edge, then to weld a bead on the bead and so on until the approximate shape of the blade was built up of nothing but filler material. That's kind of the re-shaping method i had in mind for grips as well when it comes to adding material.

Boat props also tend to be made out of whatever extra aluminum crap can be found on shop floors i think, and although it casts fine it welds horribly, like you describe with grips above, and it's really hard to burn the impurities out of what amounts to a sheet of aluminum between 1/4 and 1/8 of an inch thick. I suspect it would be more possible to cook out porosity on a one-off grip by letting it cool and going back at it until you got it nice than it would be if you were trying to do 50 a day or something.

I wonder too how something like Nibral would be for a grip. It casts, welds and machines really nicely, and although it would probably be more expensive, the heavier grip might actually be nice for balance. It would also look really keen when buffed mirror bright.

[PeterGustafsson]

Hi!

Originally Posted by migopod

I wonder too how something like Nibral would be for a grip. It casts, welds and machines really nicely, and although it would probably be more expensive, the heavier grip might actually be nice for balance. It would also look really keen when buffed mirror bright.

About that alloy:

Originally Posted by Matweb

Ampco Metal AMPCO® M4 Nickel-Aluminum Bronze, Extrusion, 25.4 - 101.6 mm.
Categories: Metal; Nonferrous Metal; Copper Alloy; Bronze

Material Notes: The patented process gives AMPCO M4 mechanical properties beyond the range of commercial nickel-aluminum bronzes, comparable to beryllium copper at a lower cost and without the beryllium copper industrial hygiene requirements.

Applications: AMPCO M4 was initially developed as an aircraft specification alloy for gears in retractable landing assemblies, engine spacer bearings and other similar applications. It is rapidly growing in use where higher mechanical properties at elevated temperatures together with corrosion-resistant properties are required. Typical applications include aircraft landing gear bearings and bushings, bending dies (shoes and mandrels) for the tube bending industry, gear wheels and wear/guide plates, etc..

Composition Notes: Copper content calculated from balance.


Physical Properties Metric English Comments
Density 7.45 g/cc 0.269 lb/in³

Mechanical Properties Metric English Comments
Hardness, Brinell 286 286 HB 30
Hardness, Rockwell C 29.0 29.0
Tensile Strength, Ultimate 965 MPa 140000 psi
Tensile Strength, Yield 724 MPa 105000 psi 0.5%
Elongation at Break 8.00 % 8.00 %
Reduction of Area 12.0 % 12.0 %
Modulus of Elasticity 124 GPa 18000 ksi
Compressive Yield Strength 689 MPa 99900 psi 0.1% Perm. Set
Compressive Strength 1324 MPa 192000 psi
Charpy Impact 7.00 J 5.16 ft-lb
Fatigue Strength 352 MPa
@# of Cycles 1.00e+8 51100 psi
@# of Cycles 1.00e+8
Shear Strength 538 MPa 78000 psi

Aluminum, Al 10.5 % 10.5 %
Copper, Cu 77.7 - 78.2 % 77.7 - 78.2 %
Iron, Fe 4.80 % 4.80 %
Manganese, Mn 1.50 % 1.50 %
Nickel, Ni 5.00 % 5.00 %
Other, total <= 0.500 % <= 0.500 %

Data from:
http://www.matweb.com/search/datashe...d=14979&ckck=1

I do not know exactly which alloy composition you were referring to, this just happened to be the 1st that popped up on a Google search for Ni-Al bronze.

Anyway, does that not seem as if the properties are way too good for this application?

Look at the density. It is almost the same as for steel, but about 3 times heavier than an usual aluminum grip. If that great weight increase is OK, would it not be easier and cheaper to use an iron alloy? One does not really need +700 MPa of tensile yield strength here.


Have a nice time!

Peter Gustafsson
MSc. in Mechanical Engineering

[DangerMouse]

Originally Posted by Nolano

If I can get my hands on a spare grip, I'll give the welding a shot. I'm a professional welder, although I work in steel mostly, not aluminum. I'd like to try it.

I can get you a half dozen spare grips to play with as long as I get some of the results if anything turns out Just let me know and I can even bring them to EFC some night.

[migopod]

Originally Posted by PeterGustafsson

Hi!

....

Look at the density. It is almost the same as for steel, but about 3 times heavier than an usual aluminum grip. If that great weight increase is OK, would it not be easier and cheaper to use an iron alloy? One does not really need +700 MPa of tensile yield strength here.


Have a nice time!

Peter Gustafsson
MSc. in Mechanical Engineering

I was thinking of the particular alloy that they use for mostly shaft-drive boat propellers (I don't know the exact proportions of constituents).
It is pretty dense compared to aluminum, but it's very pretty (if you like brassy metals)

I'd think it could be preferable to iron alloys for grips since it wouldn't rust, and it's much easier to cast and machine, especially if it were a backyard project.

Also the impact resistance might be very good for people with really really bad distance.

[fencerbill]

A heavy grip might work better for Epee than for Foil.

A heavy grip might be preferred if heavy, relatively, blades were preferred. As opposed to, say, LP folded blades. Might also depend on tactics: i.e., an emphasis on defense and parries as opposed to offense and Epee flicking. Although a successful Epee flick might really hurt.

"Buffed mirror bright." Does that imply slippery? not sure that is best unless you want to hang a trophy on the wall.

[migopod]

mirror bright would actually be pretty slippery unless you use one of the grippy gloves. Brass also looks keen with a wire-brushed finish which would provide a bit more friction.

[Nolano]

Originally Posted by DangerMouse

I can get you a half dozen spare grips to play with as long as I get some of the results if anything turns out Just let me know and I can even bring them to EFC some night.

Alright, I'll take you up on that. Personally I was thinking an attachment somewhat like what The Reluctant Fencer did. If you'd like to try something else, I could do that, too.

Paul said that the next time he went over to the U of O to fence with you guys, he'd let me know so I could go with, but seeing as he pulled or maybe tore his hamstring, and won't be doing too much fencing, I'm not sure if that's gonna happen too soon.

Originally Posted by migopod

I'd think it could be preferable to iron alloys for grips since it wouldn't rust, and it's much easier to cast and machine, especially if it were a backyard project.

I've actually thought about making a grip from several pieces of chrome molybdenum tubing, welded together... It would be lighter than a solid aluminum grip, and quite possibly stronger. It might end up being a russian style grip, though, as I'm not sure I'm anxious to build up that much material for filing out finger grooves.

[Cookeit]

So...
Both plasti-dip rubber coating and spray on textured paint were mentioned in this thread.

Which works better?

[fencerbill]

Originally Posted by Cookeit

So...
Both plasti-dip rubber coating and spray on textured paint were mentioned in this thread.

Which works better?

I used the plasti-dip rubber coating and didn't care for it. It didn't stick very well and chipped very quickly. Difficult to apply and once you open the container, what remains doesn't last long.

I like Nashua Tape Products Stretch & Seal silicone sealing tape. It sticks to itself to the point it is recommended for waterproof coverings for electrical connections. For less than $6, I got 10 feet which is enough for about half a dozen grips.

A major advantage is that any bare spots can be patched with a couple of additional inches.

Got mine at Home Depot, not sure which department. Black or transparent.

[Nolano]

I think plastidip works better for this kind of thing if you use the spray can version, and make sure you sand your grip well. I haven't tried it, but i would expect better results than out of a paint can.