Planer tearout (formerly Planer snipe)

How do you ever noticed that sometimes things work exactly the opposite to how you think they do?

I was planing some redwood yesterday and noticed the planer running slow and bogging down. I was getting a nice smooth surface, so while I thought that maybe the blades were getting dull, I didn’t think they would be really bad. I just figured that as usual I had bought a cheap tool and it couldn’t handle the task.

I have a spare set of blades laying around, so I threw them in and fired up the planer once again. I was moderately surprised to see the increase in speed of cutting with the sharp blades, obviously the old ones were much duller than I thought they were. But the real surprise, and the point of this post, was to see a marked increase in the amount of tearout.

Wouldn’t you expect to see more tear out with a dull blade than with a sharp one?

 

I don't know if a dull blade versus sharp ones makes any difference with snipe. It is always best to plane the boards before you cut them to llength! Sometimes I'll run a board thru and get no snipe at all - I don't know why.

 

I haven't had any redwood in a while, and suspect that it might not matter quite as much as some other woods, but were you running the grain through the same way the second time around?

 

I know I said snipe in the title, but was too lazy to fix it. I’m actually talking about tearout.

Pedro, this is interesting redwood. It’s reclaimed and about 50 years old, and seems even more brittle than the usual redwood. It’s very straight grained but I tried every which direction, with the same results.

 

Some wood does that. All you can do is feed slower... if that's not possible, take less thickness off at a time.

 

Dull blades might be pounding down and burnishing the soft redwood rather than getting a clean cut. Burnished wood can give you trouble absorbing stain & paint.

Was this wood reclaimed from above ground or under water? Silt from the riverbed can be trapped in the pores and dull your blades very quickly. Even above-ground wood can have a high silica content. Cedar that grows in swamps is known to have this problem.

 

I corrected the title to (hopefully) avoid any more confusion. Some members are commenting on snipe...

The problem with tearout and chipping occurs along the entire board as it is being planed. Snipe only occurs at the beginning and end of the planing process.

 

Ya, I thought the thread was about snipe issue. I always thought tear out had more to do with the condition of wood being planed. I've don't recall it ever being an issue with new wood but have run into a good bit with old wood,

 

Try wetting the wood down with a sopping wet rag for a few minutes. Its possible that the wood is so dry that it wants to chip off as its being planed.

 

Thank you all for comments and assistance. Wetting it, I’ll try that. Can’t hurt.