"Bruised" wood

[Tyler Bancroft]

I was planing some rough cherry boards, and on one I found a series of darkish "bruises" in the wood underneath a particularly deep set of milling marks. I've planed the wood smooth over them and there are no indentations. I'm assuming this is some sort of crushed/damaged grain from the milling - is there a way to deal with it other than living with it or planing off the affected wood? I'd rather not do the latter, as the marks seem quite deep.

[John K Jordan]

I was planing some rough cherry boards, and on one I found a series of darkish "bruises" in the wood underneath a particularly deep set of milling marks. I've planed the wood smooth over them and there are no indentations. I'm assuming this is some sort of crushed/damaged grain from the milling - is there a way to deal with it other than living with it or planing off the affected wood? I'd rather not do the latter, as the marks seem quite deep.

Hard to know without see it or trying, but if the "bruises" are dents they can sometimes be raised with water or steam. I use the old trick of a hot iron over a wet cloth or piece of paper towel. To avoid steaming a large area I use a soldering iron and work on one small spot at a time. Since there are no indentations now (if the surface was planed down, this may raise the dent above the surface. I can't guess what it would to do the color; I suspect not much.

JKJ

[Brian Henderson]

No way to know for sure, but since these were rough boards, are you sure that there is no metal in the wood? Iron will give a dark bluish stain to the wood if it's left in for a long time.

[Eric Sizer]

Hard to know without see it or trying, but if the "bruises" are dents they can sometimes be raised with water or steam. I use the old trick of a hot iron over a wet cloth or piece of paper towel. To avoid steaming a large area I use a soldering iron and work on one small spot at a time. Since there are no indentations now (if the surface was planed down, this may raise the dent above the surface. I can't guess what it would to do the color; I suspect not much.

JKJ

Would a trick like that work on the corner of a board that I dropped on the concrete floor? I'm making some walnut dovetail boxes as Christmas gifts and I got careless...

[Zachary Hoyt]

If you have a dent or area of crushed (unfinished) wood a household iron will pop it back up to the surface. It takes a few applications of water followed by the iron, at full heat, for a few seconds. Once the water is gone add more and keep going like this till it stops getting better. If a chip is missing of course this will not help, it won't expand wood beyond its original size. I've had to do this a few times after dropping parts I was working on.
Zach

[John K Jordan]

Would a trick like that work on the corner of a board that I dropped on the concrete floor? I'm making some walnut dovetail boxes as Christmas gifts and I got careless...

I'd certainly try it, nothing to lose, It might depend on how mashed it is. As mentioned, it might take a while and repeat attention. I've recovered from a couple booboos that way on wood turnings. I soaked water directly into the wood then applied steam with a hot iron through a wet cloth, not steam from a steam iron (but that might work too.)

One thing I might try if I had a scrap of the same wood is dent a corner on purpose to match and experiment first.

JKJ

[Zachary Hoyt]

I use a sponge or rag to apply some water right to the spot that is affected and maybe 1/4" around it, then I put the iron on the wood for 3-5 seconds, pick it up and look at the spot. If the water's all evaporated I wet it again. I keep the iron turned all the way up to the highest setting. If I left it on the wood for too long I'm sure it would burn, but I take it off pretty fast. If it's the corner that's dented I just put a little bit of the iron on the wood, but in the plane that the wood was in before it got crushed. On a corner you may have two or three possible sides from which the iron may approach, depending on the shape of the corner. It only takes about a minute to pop the wood back up with a few wettings and ironings, once the iron is hot.
Zach

[peter gagliardi]

Hard to understand without pics, but from your description about “under heavy milling”, I suspect “chip re-entrainment”
Essentially, your dust collector is not pulling all the chips away after the knife exits the cut, and some of the chips follow the knife around, and get under the cut and dent the freshly planed surface. Also, some chips may make it under the outfeed pressure bar or outfeed roller.