Chainsaw sharpening tips to cut cocobolo

[Mauricio Ulloa]

Hi,

I use my chainsaw to cut cocobolo logs, but it tends to dull very quick and the cut gets dark. I've been trying to follow the angle of the teeth in the saw, but it seems that it is not enough.

Which angle is needed to cut this exotic hard wood? Is there another type of saw that is recommended the most?

I use a gasoline Poulan 16".

Thanks,

Mauricio

[Jim Koepke]

Your profile does not list a location, but if you are close to me, bring them by and I will use my saw and sharpen yours for wood.

Honestly though, cocobolo is a tough wood. It dulls all kinds of tools.

Not sure of the silica content, but that may also have something to do with it.

A longer chain has more teeth meaning less wear per tooth when cutting.

jim

[Harvey M. Taylor]

I am with Jim on this. it comes from the coastal areas of central and south America. Prettiest grain from there interior wood is bland looking, so they say.t is oily and heavy. wont float in water.Max.

[Kyle Iwamoto]

No offense intended, but the saw is not a top notch saw, so it probably has a low quality chain. If you go to the big box stores, you should get an Oregon chain. That will probably help. I 've turned cocobolo, it is hard on your tools..... Yes, (for you flamers) there are better chains out there, but the Oregon is readily available and not that expensive.

I've not cut cocobolo. Just curious on how you got a whole log. While on that subject, since it's rather valuable, (in my mind) wouldn't you want to use a band saw, so you're not wasting 3/8" of wood or more using a chainsaw?

[Nathan Hawkes]

Okay; based on your name Mauricio, I'm guessing that you're cutting "on location"--meaning where the tree fell, which is probably nowhere near a bandmill. Still, even if you had one, you'd still have to crosscut the logs. I use a chainsaw pretty frequently, and when I have troubles like you're describing, I first check the depth rakers--these are the points in between the cutting teeth that regulate the amount of shaving the teeth can remove on each pass through the wood. As you sharpen the saw tooth, it gets progressively shorter and shorter--you need to constantly remove metal from these depth rakers over the lifetime of the chain. For most chains, the height difference you want is roughly 0.025-0.030, or, slightly less than 1/32" lower than the very tip of the cutting tooth when you look at it from the side. For your hard, hard cocobolo, you probably want to stay on the smaller side of that range--maybe even 0.020". As already said, that 16" Poulan isn't going to win any contests, but there's no reason it shouldn't work for cutting the logs. Good luck, and be careful. If you're having to push really hard into the wood, the chain is dull, or the depth rakers are too high. Whatever you do though, don't get the rakers too LOW. You'll lose control of the saw, or it will kick back. Stay safe, Mauricio, and send me some of that Cocobolo!!

[Mauricio Ulloa]

Thanks for the advice and the offer of helping me sharpen my saw.

I live in Costa Rica and I get the wood delivered to my shop in logs that I cut with my chainsaw and with my band saw. Unfortunately, it is very expensive to get the wood cut at the mill.

I'll give it a try to the oregon saw with low rakers. Probably until I'm able to get a bigger chainsaw that dulls less.

Thanks!

[Kyle Iwamoto]

Your Poulan is an okay saw, it's just the chain that needs upgrading....

[Josiah Bartlett]

I've milled a lot of walnut with an alaskan sawmill setup, which is also hard on chain saw chains. If you are ripping it, get a dedicated rip chain. Using a regular chain to rip hardwoods overheats the teeth and dulls it very quickly. If you can get ahold of a dedicated rip chain in Costa Rica, do that and it should stay sharper longer. Also, sharpen it immediatly as soon as it starts to slow down. Running it dull ruins the temper in the metal and it won't stay sharp.

If you can't find a rip chain for your saw, you can make one. You can file the teeth with a 5-10 degree angle instead of 30 like for crosscut, and leave the rakers a bit on the high side. I've had good results filing off alternating sets of teeth, but leaving the rakers behind. You have to do it so you still have an equal number of left and right teeth remaining so the chain cuts straight. Remove a set of right and left, follow by leaving a set, then remove another right and left, all the way around the chain. The chain will still cut well with half the teeth, but it will remove chips much better and won't overheat in the cut.

[Mauricio Ulloa]

Hi Josiah,

Where do you get your rip chains? I've been looking in the internet for them and I can't find them.

Thanks for the advice!

M

[Nathan Hawkes]

Mauricio, check this out:

http://www.baileysonline.com/category.asp?catID=83

[Ryan Baker]

Wow. I wish I had a big enough piece of cocobolo to need a chainsaw to cut it. Heck, I wish I had a piece of cocobolo big enough to need a baandsaw to cut it.

Yeah, probably not much you can do other than get an extra chain or two (the best you can, since they probably have better steel in the teeth), and keep them very sharp. Cutting hard or abrasive woods are just going to need more frequent sharpening.

I wonder if anybody makes a chain with carbide teeth? It would be expensive, but would be really useful for certain jobs.

[Nathan Hawkes]

Stihl makes a carbide chain for their rescue saw--sold to fire depts, and rapco makes one as well. I think they are a couple bucks for each cutter link---on the average 20" chain, there are 72, just for reference. They are very expensive, and if you hit anything buried in the wood, well it'll be an expensive learning experience. They also have to be sharpened with diamond files. I would've thought that the cocobolo would cut nice; all the oil in the fibers would seem to make it cut cleanly. Wish I had the chance to cut some too! The darkening of the cut that you're mentioning is from friction--you could be actually getting not enough oil to the chain, or as I mentioned, the rakers are too high. Yes, cocobolo is dark, but you already know that if you live in Costa Rica. I also have milled quite a lot of wood with an alaskan chainsaw mill and a 95cc Husqvarna 394xp, and have found that Carlton brand chain (also sold by baileys as "woodland pro" ) keeps an edge longer than oregon. Oregon seems to be a softer steel to me. Just my experience. As for cutting with the rip chain, I do it, but it definitely has a better chance of kickback, for whatever reason. The MFR's actually state that on the chain, and I have found it to be so. It cuts slower than crosscut chain because it takes a smaller shaving each pass; but for this reason it makes a cleaner cut.

[Josiah Bartlett]

Hi Josiah,

Where do you get your rip chains? I've been looking in the internet for them and I can't find them.

Thanks for the advice!

M

It's been about 7 years since I bought a new one, and it was in a local chain saw store. Sorry, I don't know where I would order one.