Mystery device

They're both scraping masters. One for checking flat surfaces, the other for dovetails.

Am Samstag, 22. Februar 2020 02:33:25 UTC+1 schrieb Ned Simmons:

Thanks. So you put blue compound all over the surface and then gently drag the master over it?

Chris

Replying here because I had to open your reply in Google groups...

Yes, that's essentially how they're used. If you look into it you'll find endless advice on how exactly to spread the blue, how thick, how to wiggle the master, etc.

They do have some value. Search the sold listings on ebay for "camelback straight edge".

Am Samstag, 22. Februar 2020 16:43:47 UTC+1 schrieb Ned Simmons:

Sorry. I've been using Google Groups since my last machine with Netscape 7 died.

I think I might keep the masters now. I might like to use them one day, and they're rather attractive.

Any idea what brand of scraping tool is good, and how much a tool would cost? I'm guessing scraping works much better on cast iron than mild steel. Is that right?

Best wishes,

Chris

For scrapers see:

When I was working in the trade I kept a small triangular scrapper in my tool box for deburring the edges of holes (along with an 8" double cut file for deburring outer edges of things :-)

Well then it's a shame that you posted such gargantuan image files. I quit after I got about the upper 1/3 of Mystery_Device1.JPG on my screen.

Am Sonntag, 23. Februar 2020 02:47:42 UTC+1 schrieb Sea:

Alright, I'll try to scrape a bit off next time :-).

Get off my planet! ;-)

Get out of my Solar System! :)

On 2/22/2020 7:34 PM, Christopher Tidy wrote: ... I'm guessing scraping works much better on cast iron than mild steel. Is that right?

I've never heard of anybody scraping mild steel, but what do I know. My opinion is that mild steel is not stable enough to hold the precision that one is scraping for. CRS especially has internal stresses that would make it unstable.

I think it's a problem on my end. Recently I started getting errors trying to open certain messages, haven't been able to discern a pattern.

Yes, cast iron is easier than mild steel. I don't have a lot of experience, and out of necessity much of it's scraping Turcite. I have a couple Anderson scrapers with tool steel blades. Sandvik makes carbide scrapers -- I'm sure there are others. Much of my early struggles involved proper sharpening, including getting the right geometry on the scraper edge and recognizing the difference between a dull tool and bad scraping technique.

But "scraping" is simply the removing of small amounts of material with a "scraper". I've scraped babbet, bronze, cast iron and steel.

Go find Keith Rucker on youtube. he and a few others are making camelbacks and other straight edges at the moment.

You're right. I was thinking in terms of using the OP's straight edge to scrape machine ways, for instance.

Get off my tiny crushed sea shells which act as my lawn!