Advise on driving an 18" circular saw blade

So get a decent electric chain saw and build a chop saw style mount for it. An 18" circular saw isn't going to be any quieter than an electric chain saw and both will need sharpening periodically. I expect sharpening for a length of chain will be cheaper than an 18" blade as well.

Pete C.

Rapco in Vacouver, WA has been making carbide tipped chain saw chain for a lot of years. They make a lot of it for fire departments, etc. Good quality and nice folks.

Ron Blehm Rapco

6000 NE 88th Street, #D-104 Vancouever, WA 98665 360-573-0090 snipped-for-privacy@rapcoindustries.com

An 18" saw blade is a lot of saw blade. At that size you start to get into serious issues about steel tension. The outer rim runs so much faster than the inner rim that it wants to dish over on you. If you hit the wrong freguency it can wobble uncontrollably.

Circumference = pi x diameter

3" diameter = 9.4" circumference 18" diameter = 56.5" circumference

9.4" at 600 rpm = 5.3 mph

56.5" at 600 rpm = 32 mph

Things found in logs (from Internet list)

a side-harrow tooth.

an old lead musket ball counted rings and it was about 100 yrs old.

I hit a small metal box. as it had a small quantity of gold dust and flakes in it. One of the benefits of sawing in California!

a Coca-Cola bottle

two 6-inch diameter by 8-inch long rocks, sitting vertically.

I cut into a nylon rope

an automotive-type water pump

a piece of a steel T-post one day. The sawhand who cut the tree felled it toward the old fencerow, not knowing it was there. The tree fell directly on top of one of the posts, driving a piece about 6" long into the tree and driving the rest of the post completely into the ground out of sight!! When the log hit the ground it apparently rolled enough to break off the imbedded piece and no one saw it until the sawyer cut into it at the mill.

four railroad spikes on one side of the log, three railroad spikes and an 8-inch lag screw on the other.

including animals (raccoons, squirrels, mice, cats, snakes and of course bee's honeycombs)

disk blade with the 12-inch bolt holding it into the tree. A

1/2-inch rebar

a metal-jacketed 50 caliber round. T

an anvil,

horseshoes

railroad spikes and one time I pulled 18 electrical staples out of one place in a walnut log.

sap spiles (to drain the sap for Maple sytup)

a deer stand

an ants' nest

a 3/4" wire rope

Shrapnel in a teak plank form ex-Rhodesia, now Zimbabwe. Apparently, finding bullets or shrapnel in trees from that area of the world is very common.

an old wrought iron fence straight through the middle.

a mushroomed ball of lead about an inch in diameter

nails

insulators

a metal roofing cap several feet long.

a live 50 caliber shell.

a spoon made from lead.

a training grenade from WW1.

a three inch hollow with an old five cent coke

My helper was cutting up the branches of a felled Virginia pine when a section of about 8 inches burst into flames, producing a bright white light like magnesium burning. There was a water hose nearby, and he instinctively tried to flood the flames with water. It continued to burn - this was not pine resin. Finally, after repeated attempts to put it out, he decided to just pile the rest of the freshly cut, very green pine tree on top of the fire. Even with all the water from the hose, the flames ignited the whole tree into a blaze. I have a degree in biochem, and all I can figure is that some sort of explosives or fireworks, or a form of magnseium, etc. had been in a hollow, and the tree's new growth calloused over it.

We also found an old 1940(?) generator in a tree, old bullet slugs, rocks many feet up... The most unusual was in a healthy, sound red oak. It was huge, so we took it down from the top. It was between two houses, and over one of them, about 55 feet up, I discovered that the fork I had been depending on was, to my horror, hollow. I can not believe it did not break from my weight and the ropes and pulleys, plus the shock loads and leverage/distance over the house. So I am cutting off sections about one foot at a time, 56 feet, then 55 from the ground, and a small hollow appears - packed with dirt. It was about 9 inches, with no opening to the outside air. I cut it off, drop the section, and dirt sprays the homes like a huge dog with diarrhea. When I make another cut, many little skinny red worms pop up squirming. I suppose it was an old squirrel nest in a hollow which eventually calloused over.

a live monkey from the local zoo

When I was cutting wood for sale (8-10 hrs a day, 6 days a week) I managed to wear out about a chain and bar every month. If you don't hit dirt or a piece of steel or stone while cutting that chain will stay sharp for a long time and even then it would take about 5 minutes to hand file the teeth and repair any damage, normal touch up to the teeth takes about 2 minutes. Also used a 40" buzz saw for limbs and smaller wood that was powered for the OLD F-20 I used as a power source for the saw and an elevator to stack split wood. Neat to use but VERY dangerous as well. That saw has 18" of exposed blade spinning in front of you on top of the bed. One misstep and folks will be calling you Lefty or Cap'n Hook for the rest of your life.

Your idea on carbide is also wrong it will dull just like a chain if it hits steel or stone tried a carbide chain myself due to mud on the logs. They worked OK but not well enough to justify the price.

Carbide chain is easy to get but not really worth the bother unless you have a real need like concrete or fire service demolition work. You can also get diamond bonded chain if you cutting into mixed material like reinforced concrete. We have a demo saw in one of the engines at the station just for difficult work like cutting cars apart or cutting through roofs to provide ventilation that came with carbide.

A common maximum rpm for an 18" blade is 3,800.

I found the article on critical speeds and will be happy to email it to you if you wish.

tom