i recently became interested in the use of marking knives instead of a mechanical pencil.

would it be bad to use a marking knife with a aluminum layout tool? does anyone have experience with scratches or the red coming off?

i've been practicing with a box cutter and cheap empire straight edge i have. (by the way, i use the term "straight" very loosely) i haven't noticed any scratches on the empire but i dont know what kind of aluminum or steel that is made of.

any opinions would be appreciated.
thanks

As John Economaki pointed out to me, the aluminum oxide that forms during anodizing is the same stuff they use for sandpaper. It's pretty danged hard. A lot harder than, say, brass.

That being said, I'd be pretty careful with a marking knife on aluminum. Steel shouldn't be a problem. It'll depend somewhat on the shape and sharpness of your knife.

Do you have a marking gauge? They're pretty amazingly useful...

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I don't have as many Festools as Fred. Or Marcou's, or Brese's, or Lie-Nielsen's, or Lee Valley's, or Blue Spruce's, or Harold and Saxon's, or...

You will have a better chance of avoiding scratches if you get a marking knife with a single bevel, so you can snug up the flat side against the straight edge.

Poto is right on about marking gauges. Lots of tool makers make them and different woodworkers like different ones. Here's my favorite:

http://play-glen-drake.com/v-web/eco...products_id=37

One tip I have heard is to lightly (VERY LIGHTLY) back bevel the knife. I don't remember if the reasoning for this was tracking, to prevent the knife from digging into the straight edge, or something else.

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Magic Square - for when "close enough" is good enough.
Chris Wong, Flair Woodworks & Time Warp Tool Works

thanks everybody for your great responses. it's greatly appreciated!

i'm definitely going to look into some marking gauges and the single bevel knives. after some research on the internet i read that indeed you have to be careful with aluminum. the back bevel on a single bevel knife is the way to go.

anyway, i just wanted to ask before potentially scratching up my beautiful woodpecker tools with a box cutter.

thanks again!

Thanks for sharing the results of your research.

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Magic Square - for when "close enough" is good enough.
Chris Wong, Flair Woodworks & Time Warp Tool Works