Mule Handle Build Questions

[MightyQ]

Hello Mule Fanatics!

My grandfather recently gave me some Purple Heart wood to make some mule handles and had a couple of questions about the process.

1. Are 3/16th stainless steel pins a good choice for pins? I want something that’s silvery instead of a brass color to match the blade. Any recommendations?

2. What size tubing should be used for the lanyard tube? And any recommendations of one that’s a silvery color?

3. Does this wood need to be stabilized? Or what kind of finish should I use on it?

Thanks for the help!

[TomAiello]

1). 3/16 straight pins will work fine if you have good epoxy (I like West G Flex), but I prefer Corby bolts (example: https://knifemaking.com/products/cp627- ... 0548686984). Stainless will work, but it's a little harder to sand down. Nickel silver is a bit shinier, and easier to work with in my experience.

2). I generally don't put lanyard tubes in my Mule handles. I'd have to go measure the diameter a mule to see what size to use. You can buy lanyard tube to match your fasteners pretty easily, although I'd personally go with nickel silver rather than stainless for ease of sanding down (example: https://knifemaking.com/products/metal- ... dc8b&_ss=r).

3). I would stabilize purple heart. It tends to fade out to a brownish color over time if you leave it in it's natural state. I like to stabilize it with some (relatively subtle) purple dye in the mix, to accentuate the purple wood and keep it from fading. If you're not going to stabilize it, I'd probably just use something like tung oil and apply _a lot_ of coats over many days to protect it, then continue applying it periodically. There is a thread somewhere in this forum where people are talking about coatings to use on unstabilized wood. I'm not very current to that though, because I started stabilizing my own stuff a while back, and I've gotten into it enough that I pretty much stabilize everything because I enjoy the process and results of stabilizing. Well stabilized wood sanded down to super fine grits (I go up to 5000) has an amazing shine to it. It's hard to believe how much difference you see when you work up to the super fine grits. I used to just go up to 1200 and couldn't figure out how to get that 'polished' look. Then I started increasing the finishing grit, and the difference was stunning.

[RustyIron]

1. Are 3/16th stainless steel pins a good choice for pins? I want something that’s silvery instead of a brass color to match the blade. Any recommendations?

I've only done two Mules, and on both I used 3/16" dowel pins, like would be used to precisely locate/align engine parts or jigs for machine operations. Those that I have are some kind of high-zoot steel, like you'd use in your F89 Scorpion. Despite being 60+ years old, there's not a speck of rust. You can come and pick some up if you're local, or I can hand some off to the mailman later this week. If it's stainless you're after, McMaster-Carr will send you a box full for less than ten bucks.

Like Tom suggested, you need to be gentle when working with metal and wood together. If you're using a grinder or sander to get the pins close to the finish size, you have to go slow as to not overheat them. Get them too hot, and you'll discolor your wood and probably goof up your epoxy.

[Xplorer]

1. 3/16" is a good size. Stainless is going to look good and it will work. It's a little hard to work in comparison with the wood that will surround it. Nickel would be easier and will also provide the silvery look with the addition of total stain resistance.

2. I use 1/4" tube for lanyards. Nickel, again would be my suggestion. However, stainless will work and I'd rather use stainless for a lanyard tube than for a pin. The stainless pin is more likely to end up "proud" above the surface of the wood than a lanyard tube would be.

3. The only time I've used purple heart I stabilized it. I would suggest stabilizing it as it is not one of the high hardness and high oil content wood species that would be best for tool handles without stabilizing. If you do not stabilize, I suggest daily treatment with boiled linseed oil for about 7 days in a row, then finished with a good wood wax. Follow up with linseed once a month for 3 months, then once again 6 months later, and then re-apply once per year after that.

Like Tom said, purple heart will darken to a brown color if not protected. Stabilizing in clear resin will help a lot. Tom's suggestion of adding a little purple into the resin would be even better.

Here's the purple heart I stabilized in clear resin just after I finished the knife..


Here it is today after about 1 year of occasional kitchen use.


The lighting in those 2 shots accounts for some of the color shift you can see but not all of it. It was lighter in color and more "red" purple when it was new and now it is darker and more true purple. Non-stabilized purple heart will not stay this purple looking and tends to get more brownish over time.

Also, if this is your first handle you might find more answers to questions that arise here as well. viewtopic.php?f=15&t=89740#p1525384

Best regards,
CK

[sal]

Hi MightyQ,

Welcome to our forum.

Hope you enjoy your time here. The group here that is into Mules is very knowledgeable and willing to share.

sal

[MightyQ]

1. 3/16" is a good size. Stainless is going to look good and it will work. It's a little hard to work in comparison with the wood that will surround it. Nickel would be easier and will also provide the silvery look with the addition of total stain resistance.

2. I use 1/4" tube for lanyards. Nickel, again would be my suggestion. However, stainless will work and I'd rather use stainless for a lanyard tube than for a pin. The stainless pin is more likely to end up "proud" above the surface of the wood than a lanyard tube would be.

3. The only time I've used purple heart I stabilized it. I would suggest stabilizing it as it is not one of the high hardness and high oil content wood species that would be best for tool handles without stabilizing. If you do not stabilize, I suggest daily treatment with boiled linseed oil for about 7 days in a row, then finished with a good wood wax. Follow up with linseed once a month for 3 months, then once again 6 months later, and then re-apply once per year after that.

Like Tom said, purple heart will darken to a brown color if not protected. Stabilizing in clear resin will help a lot. Tom's suggestion of adding a little purple into the resin would be even better.

Here's the purple heart I stabilized in clear resin just after I finished the knife..


Here it is today after about 1 year of occasional kitchen use.


The lighting in those 2 shots accounts for some of the color shift you can see but not all of it. It was lighter in color and more "red" purple when it was new and now it is darker and more true purple. Non-stabilized purple heart will not stay this purple looking and tends to get more brownish over time.

Also, if this is your first handle you might find more answers to questions that arise here as well. viewtopic.php?f=15&t=89740#p1525384

Best regards,
CK

Wow Xplorer that Looks amazing, I would love for mine to end up that purple color as it is currently more aligned with your first photo's color. You say just over time it turned more purple? hand oils maybe? Very nice, and your post of the mule handle build is actually what I have been referencing! Great info on there. I would love to recreate your coke bottle shape and I'm gonna give it my best!

And thanks everyone else for the great information, it's a very good feeling having all this outside help. Attached below is my current progress.

[Xplorer]

Looking good so far! ^

No I don't think my handle turned more purple from hand oils. That knife doesn't get used all that much. My best guess is the color shift is a result of oxidation. Stabilizing fills the air gaps in the wood grain with a resin, making it much more impact resistant and much more resistant to water and chemical damage. But, while it dramatically reduces the amount of surface area that can be affected by oxygen, it doesn't seal out all oxygen (or liquids) completely. My hunch is we are simply seeing a much slower and more limited version of the same darkening you would see without stabilizing.

[MightyQ]

Thanks! Yeah that makes sense, very nice color! I actually found out through trial and error that through the use of heat it turns the wood more purple as well so I may lightly torch it to bring out some of those deeper purples.

[Xplorer]

That makes sense. Heat would be speeding the oxidation process. In fact, the definition of burning is "mixing with oxygen" so when you heat the wood you open the molecules up to a greater degree of oxygen exposure. The oxygen "burns" the molecules which causes them to darken.
Oil in your car is a good example of the same process...when the oil's additive oxidation stabilizers break down the oil begins to absorb oxygen at the molecular level and degradation can be seen as darkening which eventually turns the oil from amber to black.

[Bolster]

After finishing to shape, try wiping your purple heart with acetone.* Or super-charge it with several wipes of acetone interspersed with several hours of bright sun exposure (for UV) on day one. Let the oxidation continue indoors on day two. Then, finish your scales with a finish that has UV inhibitors, and limit further UV exposure, which will serve to "brown" the purple heart. Should give you some very purple, purple heart! If you don't get the purple you want, then photograph and tweak in Photoshop. (Kidding.)

*What you are doing with acetone is dissolving the colorful dienes in the wood and bringing them to the surface. Note that wetting introduces the possiblity of a warp, so it's not entirely risk free.

[Bolster]

The Purpleizer:

https://bkibby.wordpress.com/2016/07/24/frankenpurple/

[MightyQ]

The Purpleizer:

https://bkibby.wordpress.com/2016/07/24/frankenpurple/

Wow that’s awesome. Thanks Bolster!

[MightyQ]

Making progress and decided just to go with brass for the more traditional look, but mainly because I’m impatient and was the only 3/16th rods Ace hardware had haha. Took some advice from Xplorer’s how to and rounded and polished the top part of the handle before epoxy, got it glued up and in the vice now!