Thursday, March 3, 2011

Blacksmithing Removing Scale, Tinted Glasses, Upsetting

Blacksmithing How to Remove Scale, Tinted Glasses, Upsetting

I have a few questions for now.
If you use hot rolled steel how do you remove the scale on the parts that is not heated for forging? Do you use a wire wheel, and acid bath or sand the area?
Do you wear special tinted or filtered glasses when you do blacksmithing and have to stare at the fire alot.
I want to flare out a 3/4 square bar so that it will form a pyramid type base. If I heat it should I slam it on to a thick steel plate to flare it out. Is that the best way to do it?

Removing Scale
There are couple of options, they mostly depend on what coating you are putting on it.
Wire wheel for clear coating.
Sandblasting for paint.
Acid etch for galvanizing but this is done at the galvanizer.

Mostly it depends how you want the finished piece to look. Complex shapes may not get completely cleaned of for clear coat and painting.

Tinted glasses
Yes I wear rose dydimium glasses. This is the old filter style originally designed for glass blowers. There are other filters that are better recommended for blacksmithing such as AUR-99 from I have not used this lens so can't really comment on it. The exposure to UV and IR are generally minimal in blacksmithing, but it does become important with lots of forge welding as the temperatures are so much higher.

Upsetting 3/4 inch square bar
Depends on the length. short can be done on the anvil or clamped in the vise and a light hammer used.
Long bar yes heavy steel plate on the floor and it is sort of bounced on it.
It must be at yellow heat. You should also taper the edges (basically knocking the corners off the end of the bar) this lets the force go deeper into the center of the bar instead of being dispersed at the end. Upsettting is tricky to do well. Practice first and easier to do on a larger bar than a smaller one.

I hope this helps
David Robertson
Ontario Artist Blacksmith