Saving your edges when milling dirty lumber

[David Utterback]

When I have bought rough cut lumber over the years, much has come from barns and multipurpose shops where it had been stored for many years. This lumber always has surface contamination (dirt) which I believe will dull tools as the faces are planed, joined and cut. If you also have dealt with this problem, how do you remove the debris in order to protect your edges?

This afternoon, I used a scrub plane on some 12/4 x 4-1/2" sapele I found in my stock. Other choices I considered were a jack plane with an old blade, pad sander, Rotex, rasps, coarse files, bandsaw to make a thin cut and my table saw for the same purpose. Also considered pressure washer or soapy water plus a steel brush. Afterwards, I thought a belt sander might do the trick but I do not have one.

What do the rest of you do?
Thanks

[Jim Becker]

I use...a broom.

[Andrew Hughes]

I’ve used my bandsaw for reclaimed fir that’s has paint. I always consider the thickness of Reclaimed stuff because I know it’s there’s going to be a lot of waste.
The roughsawn lumber I get isn’t very dirty but I do usually get to pull from a lift. I choose wisely
I was gifted some air dried Eucalyptus last year and that was some gnarly stuff. I lost more then 50% of the boards the cost to cut away defects was $$.

[Mark Bolton]

Usually just suffer if we have to run it and pull the planer knives and sharpen them. You can get rid of a lot of grit by stacking up a couple brass wire Wheels on an angle grinder and knock the bulk of it off but inevitably there will be plenty left and its painfully slow.

Any abrasive option (sander/belt sander) will inevitably leave a piece of abrasive that will knick knives.

Honestly it doesn't matter if it's old or new or rough or skipped... your first pass through the planer or across any knife tool is going to leave a knick. We are taking s3s walnut to size now that was skipped and straight lined at our supplier. Brand new set of 20" knives in the planer, clean boards, and 2 boards in there was a knick in the knives.

It is what it is.

[Tom Bain]

If I'm planing reclaimed or particularly dirty wood, I will put in through a pass or two on my older lunchbox planer (a DW734) before I take it to the jointer and my better planer. I figure the knives in the lunchbox are disposable (and can be flipped to use either edge) and I can order a new set if they take a bad knick.

[Bill Dufour]

The big redwood mills used a pressure washer to remove the bark before milling. The bark can be more then 2' thick. The log was put on rollers and allowed to spin around it's long axis as it got washed.
Bill D

[Warren Lake]

There are some grown ups here ( not me ) had the best answer I think. Joe and one or two others have the fancy knives you can snap in and out. They keep an old set for nasty then snap the good ones back in. Ive only done the barn board thing once and knives were trashed and louder than running hickory. Same with Teak. Sanding before machining will dull knives as well. The snap in and out sounds very nice but likely the heads come a fair cost and for some like my combo machine would not work as there is a mortiser and tabble saw on either side of the knives. how many arms and legs for one of those heads a 20" jointer? approx 3k 2k ?

[Mel Fulks]

When you must run material with old paint ,grit,etc; run it as fast as you can. Unfortunately the natural instinct seems
inclined to going slowly.

[Steve Jenkins]

Check out Dispozablade.com. This is a reversible straight knife system you can put in pretty much any planer or jointer. The knives snap onto a backing plate and self align when you put them in the cutter head. For those familiar with the Felder knives they are very similar. I put them in my 16” Oliver jointer years ago. They seem to hold an edge better than standard knives and being reversible the cost is about the same as sharpening

[Mark Bolton]

It really doesn't matter what knife you use, Tersa, helical insert, straight, you can run a ratty set and hog off the dirt, put your cherry set back in and the first board you run you may get an knick. It's just part of the deal. At that point you resharp, offset knives, rotate inserts, or just live with it.

Planer is a roughing tool anyway. Sucks, but is what it is.

[Robert Hazelwood]

I think this is a good task for a handheld electric planer.

[johnny means]

Brush it off and get at it. What good does it do to replace one hardship with another.

[Mel Fulks]

Brush it off and get at it. What good does it do to replace one hardship with another.

Sounds like you've been watching some westerns with no nonsense "straw- bosses". We like 'em too!

[Mike Wilkins]

A swipe with a wire brush and belt sander with 80 grit. These are much cheaper than sacrificing my carbide inserts on my jointer/planer.

[John K Jordan]

A swipe with a wire brush and belt sander with 80 grit. These are much cheaper than sacrificing my carbide inserts on my jointer/planer.

I use a wire brush before processing dirty wood on my bandsaw. I hate it when I see sparks from hitting a flake of gravel embedded in the wood or bark.

JKJ