Thread: Finding nails during milling

I have one of these, which seems to find the deep nails too. Not sure whether it's worth the premium price compared to the cheap generics, but it only needs to save one decent blade to make it worthwhile.

But I think you just have to accept you're going to miss the odd bit of metal if you insist on doing green hippie stuff like recycling/repurposing/re-using. Best to stick to coal.

Unless the blade is kinked or buckled noticeably, the blade is saveable.( is that even a word?) If the individual teeth are damged or bent, I’ve just ground them off with a dremel type tool before, an angle grinder would do too, with care. a couple of missing teeth doesn’t seem to make any difference to the performance of the band.

When you inspect the blade, also look for stress cracks in the gullet or near the tip of the tooth.

Cracks in the gullet are pretty much asking for 'brown pants' moments in the near future. Best to scrap the blade now before it snaps in the middle of a job.

Cracks near the teeth aren't so bad, but the tooth will likely break off soonish. Not a major problem in itself - as said above, the occasional missing tooth doesn't matter that much when simply ripping - but you never really know what the tooth shrapnel will do in the cut.

Originally Posted by riverbuilder

Unless the blade is kinked or buckled noticeably, the blade is saveable.( is that even a word?)

Salvageable.

Thanks for the responses. I'll check the gullets. If there are no cracks I'll have a go at resharpening.
The machine takes a 2820mm blade. Do I need a blade exactly this length or is a bit bigger/smaller ok? I assume a little difference can be accounted for in the tensioning?

Metal detection sensitivity is related to things like depth, orientation and size of the metal pieces.
Most security type detectors are designed to pick up relatively large pieces of metal so may not be as effective.

I have one of these Carbatec Metal Detector | Carbatec
This detector uses the same circuit as many security type detectors but seems to be more sensitive in that it can detect a staple under about 5mm of wood, and I have detected 2" nails down to about 50 mm.

The main problem is remembering to bring the detector to the worksite and then to use it. The biggest thing I hit with a chainsaw was a large coach bolt but it was made of soft steel and the chain cut right through it with hardly loss of cutting edge. The hardest metal was a Tek screw which broke 3 cutters (easy enough to replace and refile to size). The thing that caused me considerable pain was a 10 mm braided harden steel rope/wire wrapped around and buried in a log. After cutting through it twice I stopped milling that log - couldn't even use it for firewood.

If you are lucky you might see a black stain in a cut piece indicating that something nasty is buried further down.

Urban trees are notorious for "stuff" buried in the wood. Metal is relatively easier to deal with compared to things like glass, concrete, ceramics (electrical transmission line insulator) and rocks.

lol
I think my nails were about 50mm, possibly a little longer.

I have ordered two blades (carbon steel on the assumption that I'll hit something nasty before their service life is up).
Both nails were on the same side of the log. I'm wondering whether I jettison the log or give the opposite side a go.

Have also ordered a metal detector because it's clear visual inspection is not good enough.

So when you locate an embedded nail with the detector what next? Do you cross cut around it?

Originally Posted by Stopblock

So when you locate an embedded nail with the detector what next? Do you cross cut around it?

Depends on the wood, if it's an urban tree and something I already have some of I usually leave it alone.
If it's something worth while I might chop around it with a 1.5" Chisel, follow the black stain. Or like you say, cut from the other side and watch for the stain again.
If its a big stain I might plunge cut with the chainsaw around the stain.

The biggest problems is with non-metallic stuff iin crotches etc where people have thrown stuff and the tree has grown around it.

Ironically, my first pass in my first attempt at milling found the only nail (extracted by chisel):
20210312_182209.jpg

Final product:

20210314_144801.jpg

Note to self: don't press upload files more than once.