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View Full Version : Scraping baby-steps



3jaw
02-26-2003, 12:49 PM
I just had to share this with everyone. I have been playing around with a hand scraper and small (2" square) cast iron angle plate. After about 45 minutes worth of scraping and spotting, I have gotten it flat enough to just stick (wring) to a dry, flat surface. Add a little oil between the two and it takes some effort to pull apart. I was skeptical about my ability to do this but it really wasn't that hard. Granted, it's not the same as rescraping the ways of a machine tool, but it is a start! Next, I would like to take 3 blocks of cast iron and generate my own surface plates.

Let's see, all I would need to do then is make a straightedge, some templates, a spindle test bar, find a climate controlled room and I can rebuild my Logan........... http://bbs.homeshopmachinist.net//biggrin.gif

Oh well, one step at a time I guess.

Greg

Tony
02-26-2003, 03:43 PM
can you expand on just HOW you scrape a piece of metal into shape?

i've seen hand scraped tools (ways, blocks, etc)... and i've heard machinists talk about it in an almost mystic way.. but i still cant get a handle on how its actually done.

not that i plan on doing any. http://bbs.homeshopmachinist.net//smile.gif

what kind of "scraper" do you have to use to shave metal like that? and is there some sort of honing compound used, that actually does the cutting??

curious,
-knucklehead.

3jaw
02-26-2003, 10:25 PM
knucklehead,

Check out this website for a pretty good description of scraping: http://www.csgnet.net/toolroom/scrape1.htm

Thrud
02-27-2003, 12:05 AM
knucklehead:
can you expand on just HOW you scrape a piece of metal into shape?
[/QUOTE]

With a scraper and LOTS of practice. "Machine Tool Reconditioning" by Edward F. Connelly is a good starting point but by no means the only way to get started in it.

If you can afford one, a Biax power scraper they can be used even by monkeys to do reasonable jobs with a little practice.

http://www.dapra.com (Biax Power scrapers, scraping supplies, & hand tools)

3Jaw

Good job. Keep at it!

[This message has been edited by Thrud (edited 02-27-2003).]

Oso
02-27-2003, 01:04 AM
Hmmm...

By following the links, I discovered that McMaster-Carr sells scrapers of the right type. A mere $150 to $190 per, considering that you have to buy the handle and blades separately. It's about $120 for the handle, and another $35 for the blade, for the smallest type, which is 3/4 wide.

Enco seems to have sold out of theirs, per messages on other sites, and will not be getting more.

I assume Dapra is in the same price category as McMaster-Carr, but I don't know. From what's on that scraping site, the McMaster-Carr may BE Dapra scrapers.

I bought the book, but I have a lot better uses for another $200 than one scraper, so I guess I will be sharpening old files!