Metal in the wood

[Dan Stromberg]

Pretty sure I'm just going to toss the blank since it's nothing special (free wood, and worth every penny!), but it has me wondering.

I think I hit some embedded metal in the bowl I was turning this morning. Gouge was running smoothly down the inside of the bowl and suddenly stopped and would cut no more. Same thing for several more gouges and scrapers I tried. (Assuming I just dulled 4-5 tools).

So, if this was an important piece, is there anything that works well to get past this? Would a carbide tool do it? Lots of aggressive sanding?

Thanks all.

 

[hockenbery]

So, if this was an important piece, is there anything that works well to get past this? Would a carbide tool do it? Lots of aggressive sanding?

I usually hear metal as a tick. I stop when I hear one and inspect the gouge. There is usually a tiny Nick in the cutting edge.
I have never considered turning to be an option for removing metal. Stopping early decreases the time to regrind a cutting edge.
If you didn’t hear a distinct tick it might be a rock or concrete fill-a popular unwise tree fix used last century.

The metal is easy to find as a shinny spot near the last circle cut
I use an old chisel and maybe a drill to cut around the metal. Nails and screws can often be removed if enough can be exposed to get vice grips on. That said I have had nails break instead of pulling out.
If it is a large lag bolt or a horseshoe I probably abandon the piece.

Good luck

I once had a gorgeous sycamore full of wasp holes and rusted barbed wire. The wire was so far gone I could cut through it with a few resharpenings. It dulled the tools but didn’t Nick the edge like a nail often does.
Lead cuts easily turned some bullets and buckshot…

Many carbide tips will fracture on contact with metal or a concrete floor.

 

[robo hippy]

Like Al said, you can hear the metal ticking as it hits your tools. If you are using M42 high speed steel, generally it will cause some damage, but not totally ruin the edge. Standard M2 HSS will get damaged to the point of not cutting any more. M42 is what they use for the teeth on the pallet cutting bandsaw blades. Not sure how the V10/Thompson tools would react, but probably very similar to the M42. Also, like Al said, I would expect the carbide to chip and/or shatter when hitting metal. You can usually see black iron stains in wood that has metal in it. Some will use metal detectors first. I have turned wood that had lead bullets in it and you do not hear any noise from that.

robo hippy

 

[Dan Stromberg]

Thanks. All I am seeing is a small black stain in the wood. One of the tools I had tried was a Thompson bowl gouge, the rest were probably all basic M2 HSS. It cut fine going down from the rim and then just stopped. I feel like I was able to gradually wear it down and if I was patient enough, I could probably get past it (I don't see it on the outside), but wasn't sure if there was a better way.

Al - thanks for the tip on the carbide, that'll save me from trying that!

My big takeaway from this is that there's no silver bullet (pardon the pun!) for getting past the metal. I might give it one last try with some 60-grit paper and then throw in the towel.

Dan

 

[Dean Center]

Very good responses and advice. Like Dan, I've had occasions where I don't hear the Tick sound and the gouge suddenly just doesn't seem to be cutting properly. Maybe because the nail or screw has gotten rotten and soft over time.

Dan, the metal object is in that stain somewhere, and I agree that you're best off finding it and getting it out. One other adverse effect of hitting it with a steel gouge is the possibility that a tiny bit of metal will come flying off from gouge or foreign object. REALLY good eye protection is essential if you're going to continue turning that piece. Just one little piece of metal, with enough speed to penetrate your eye, can ruin far more than your whole day.

 

[Dan Stromberg]

Just one little piece of metal, with enough speed to penetrate your eye, can ruin far more than your whole day.

Agreed! At the risk of overusing the phrase... "Life's too short..."

This is "mystery wood" that I got as part of a large trunkload from an estate sale. A lot of it is wormy too, so I figured it would make good practice wood. Not good "shoot your eye out" wood.

 

[Neil S]

I'm the inhouse blade re-sharpening service at out local Men's Shed... and I get to re-sharpen a lot of blades in a year, which are mostly used on recycled timber. So I often get to see what happens to carbide edges when they hit embedded metal.

The carbide will handle staples and most nails, hardly blinking at very old soft nails, while concrete nails are an instant disaster as are many screws, which are mostly hardened.

The TC grades that are used for woodworking usually have a hardness up in the low 90s on the HRa scale, so are very brittle and do not tolerate the impact from interrupted cuts, which is what a piece of metal embedded in wood represents to the cutting edge.

 

[Kevin Jenness]

You could look at it as an opportunity - turn the wood where you can and carve away the ring around the metal to expose it and leave it proud. I know of one turner who did that and sold a bowl with embedded metal for a premium to a particular customer who ran a sawmill and could appreciate the "find".

 

[robo hippy]

For really serious 'reshaping' of tools, I have a 1 1/2 hp belt sander with 36 grit on it.

robo hippy

 

[Darryl Fective]

You could look at it as an opportunity - turn the wood where you can and carve away the ring around the metal to expose it and leave it proud. I know of one turner who did that and sold a bowl with embedded metal for a premium to a particular customer who ran a sawmill and could appreciate the "find".

I had a blank with a bullet in it. The lead carved out very easily, but afterwards, I sort wished I had left it.

 

[R Henrickson]

I turned a large ash bowl long ago from a tree which had taken a full burst of birdshot midway in its life. When I first saw a little metallic gleam, I thought "Oh no", then discovered it was birdshot. I left as many as I could in situ, as well as small pits surrounded by discoloration.

 

[Tom Lucas]

I recently turned a large walnut bowl (~15") that was going to be real nice. As I was just getting it shaped for the 1st rough cut of two turnings in preparing it for drying, my gouge started bouncing and skipping. I stopped the lathe and there were a series of 4 metal objects grouped together nice and shiny in the bottom of the bowl. I'm guessing they are nails, as the previous owner of this property had a fence nailed to this tree. I tore down the fence 32 years ago. I had completely forgotten about their "handy work" until this. I've decided to leave them and will finish the bowl as a "rustic" vessel about an inch thick. The alternative is to cut out the nails all the way through the bowl and fill with epoxy or something. If I'm not happy with the rustic turnout maybe I'll do that..... or just chuck on the burn pile. I was using a Thompson 5/8 gouge. It didn't chip but definitely had to be re-sharpened. It did cut the nails clean and shiny though

 

[robo hippy]

Do not EVER take a 'barn yard' tree! Made that mistake once, and never again. Besides many nails, I found a 1/4 inch spike in it with my chainsaw, in the pouring rain as I was trying to cut it up and get it into my van. Bullets in wood are a great 'embellishment' to leave in. Had one piece of bird shot in one cherry table top once, and that sold the piece. I do have another piece of oak some where with about a 1/4 inch slug in it, no idea of caliber since I don't have any guns. The lead can leave black streaks too, which add nice color to the pieces.

robo hippy

 

[Dean Center]

When my neighbors took down a large Russian olive in their yard, I made them a couple bowls from the wood. Along the way, I found numerous nails, in clusters about 6" apart. After presenting the bowls to the family, they remarked that their boys had indeed had a tree house up above. I never expected this, as a free standing Russian olive seems like a pretty poor tree for a fort, but they obviously made do with the best tree they had. In any case, for them, the nails were a positive reminder of their family life over the years.

 

[Gerald Lawrence]

Old trick to get pecan trees to bear again (ok it may not work) is to drive in rusty nails. Back before covid I was looking for wood to make offering plates. Found a huge pecan down and went up 4 times to get blanks. Cut thru three nails with chainsaw and also found a couple bullets.

 

[Brent@TurnRobust]

A fellow in Texas found a horseshoe in a piece of Mesquite a few years ago and managed to keep the wood and the horseshoe together and turn an interesting piece from it. He had it in the instant gallery at SWAT. Not that I recommend that, mind you.