Sandblasting carbon blades before heat treat pros and cons

[Nathan House]

I have heard about sandblasting
carbon blades before heat treat
to stress releive the blade
from grinding spots or hotspots
or uneven grinding i have heard this
will help stop worppage in high carbon blade
which are good for worping
during heat treat
I would like to hear any input on this subject matter, weather it is a waste of time
to do your if it a good pratice to get into doing it also before heat treat.
thanks Nathan

 

[TJ Smith]

Don't know about the stress relief and those things but I know it sure takes a lot of sanding to get all those little pits out.
Take care
TJ
PS Take a look at the frosty area under a microscope and tell me those aren't pits.

[This message has been edited by TJ Smith (edited 09-04-2000).]

 

[Nathan House]

TJ
Thanks for your input but I am not worryed about that i am going to
oxidize the blade black
ricky fowler of fowler custom knives
does this method and he makes some fine looking blades,sand blasting and beadblasting
does not pit blades it just give the blade a texture for the oxidizings to cling to

 

[MaxTheKnife]

Hey Nathan, have a look at my post on this forum titled 'blade tumbler with steel balls' and tell me what you think.

As far as sandblasting for stress relief, I don't think you can relieve stress with that method. When I forge a blade, I use the triple annealing trick just after finsihing my main forging and before grinding to relieve stress. It really works! I had trouble with warping during heat treat before I learned this trick. After triple annealing, it's a simple matter to gently tap the blade into shape and get out those little wiggles. Also, during heat treat, I quench from the edge. That also helps on the warping.

------------------
M.Ogg

"It's better to be thought a fool and remain silent, than to open your mouth and remove all doubt"

 

[samwereb]

Max is exactly right. You need heat to relieve the streses which are built up during any machining of the steel. Sand/bead blasting just will not do it.