I have just joined, and have been thinking about purchasing a metal detector for the logs I have and will be sawing. The idea sounds good, saving your self the agravation and ear bending sound of hitting metal of any kind,( I hit 15 nail's this past week in the second cut on a 26 inch pine) but I can purchase 60 band blade's for that kind of money. I custom saw for others and for my self. Buy the way the blade that hit all those nails still lives and didn"t even lose a tooth just need to be reset. I am undesided...
Well don't put it off to long. You can get a pretty good White detector for $250 that will do the job. :Think about the time and aggravation of just changing the blade, much less what it cost you lin sharpening time or dollars.
The neat thing about a metal detector is that it is a valuable tool for finding nuts, bolts and wrenches in the sawdust as well as detecting old house sites on your lunch break.
Tom how deep do these things scan??? I have tools that scan for metal, electrical wire, pvc pipe and such but they only scan about 8". Will these things scan to the middle of a log???
Steve
My White's Classic II found a aluminum roofing nail 12" deep in an Eastern White Pine last weekend. I run the unit without metal descrimination on max power. My only wish is that I had a smaller pinpointer unit to actually help locate the piece. I have a friend with one of the big Rens units. It is very impressive. I'll borrow it for a big hardwood yard tree now and again, otherwise I just recheck the log after cutting in 6-8" or so (one of the benefits of not being on a metal deck when cutting)
It is invaluable to me because I run a Peterson Swing Blade and my blade replacement cost if I have a metallic trajedy is much higher than you band sawyers. :'(
Check out these folks for detector pricing.
http://www.kellycodetectors.com/indexmain.htm
CAPTAIN
I custom saw between 100-200 thousand bd-ft a year and average perhaps 10 foreign objects in that much material. Not every one requires a blade change, so figure 6 to 7 blade changes per year due to foreign objects. It takes a lot of logs to make 100 thousand feet, and I'd have to scan every one to be sure I didn't have metal in the log. How long would that take and how much is my time worth? I like to think that I average $25 per hour. Now, by my way of thinking, it costs a lot less to just saw inot the nails and then replace the blades as needed. Just my 2 cents worth.
Now you may think that my method is a bit of "closing the barn door after the cows are out" :), but I use my metal detector AFTER I hit something in a log. :o It has been my experience that there is normally more than 1 nail in a log. so if I hit one, I will look for the rest. Has saved me more than one blade change and I don't waste time checking the 99 out of 100 logs that don't have metal in them. 8)
The detector I use is about 20 year old Garrett A-D-S. I turn the descrimination all the way down and sensitivity all the way up. It works real well, Have not missed any yet. ;D ;D
I use a 20+ year-old Garrett too. It will find metal in logs at varying depths but I trust 6". It will find 4d box nails at that depth. The surface area of the metal means a lot to depth. You will find a nail a lot easier that was bent over than one that was driven straight, unless you detect it from the side and then you are usually dealing with more depth.
A detector has a sensitive range beneath the coil that is shaped like a cone. the larger the coil the longer the cone. A small coil will have a short cone and, while it pin-points better, hasn't the depth capabilities. My coil is a standard 9".
Once the log is on the mill you have to deal with all the metal of the mill. The detector will "find" it too. :D I can "find" my mill from a distance of about 12" and sometimes more. :-/
I don't usually check each and every log when everything is going good. You can tell sometimes when a log may have metal and it is usually the bottom 8' of the log. If I run into metal in a butt then I start looking for other butts in the pile. If I hit or find nails at 16" intervals then I definitely look at the pile. This means that some kids put a ladder in the tree and there is more ladder somewhere. The ladder also went somewhere, like to a tree house or deer stand. Deer hunters in the tops of trees will drive nails for shelves or to hang jackets or for a gun rest or a place to hang a coffee cup or thermos. I've hit nails so far up a tree that I know it had to be a deer hunter.
Most yard trees will have a nail driven in it for hanging a potted plant or a garage sale sign. Experience has proved that most of them have been stuck in there by the lady of the house. This is especially true for Red Cedars. They prune the limbs fairly close to the trunk and the end of the stumps will have a nail driven in it. The folds of Eastern Red Cedar also get nails driven into them. I've never been able to figure out why. I guess the fold grows up around the nail.
That brings up a good point. You wouldn't believe the number of people who believe that a nail grows up-wards with the tree. They don't. A nail driven at 5 feet height will be at 5' height a hundred years from now. The tree lays down wood over the top of it and it soon is hidden inside, but it doesn't move. You have to think of a tree putting on wood the same as dipping candles. When someone makes a candle, they dip it in hot wax and remove it. The wax cools as it is pulled out and forms a layer on the candle. Each dipping produces a new layer and the candle gets bigger.
On a tree, the bud grows toward th sky but the cambium grows to the side. Each growing season lays down a new layer and forms a ring. Since there is usually one growing season in a year, a ring equals a years growth. I learned from a forester friend that there is such a thing as "false" rings too. Sometimes a tree will have more than one growing spurt in a rear and these rings will make it look like the tree is older than it actually is if you don't know how to recognize a false ring. False rings usually don't go all the way around a tree but are localized growth areas. Not being an expert, I hesitate to differentiate and will usually count them as an annual ring.
Have you ever noticed that someone who is driving nails into trees will not use just one if six or eight will work?
There is a product on the market now that is used for marking logs. It is a plastic tag with plastic stubs on the corners that, when hit, drive into the butt of a tree like a nail. I'll bet there is a market here somewhere for plastic nails to be used by hunters who just have to drive nails in trees. Perhaps someone will develop it.
The other side of owning a metal detector is the fun you can have detecting around old buildings and trash piles. I saw on old homesteads a lot and there are treasures there that I love to find. I'm usually allowed to keep all of them too. There are old axe heads, hammers, knives, silverware, broken cast-iron stoves, cut nails and, sometimes, an old coin.
I use both a Garrett and a Rens
Well I think alittle more research is in order. :P I would like to thank you all for the fast responses and look forward to reading your ideas.
Thankx, Jeff