Scraping in a straight edge

@Ultradog MN
I do have Connely’s book, have read enough of RK’s comments about it to grab a copy.
 
I am sorry Members, but here is a little history lesson: Daryl, I taught you to scrape before I introduced you to Dennis (who your calling your mentor. Dennis Danish was my friend and I wanted him to observe, help my students and you were one of them at a class I was teaching in St. Paul approx 10 years ago. I invited him and that is where you met him at a class you attended as a student. I met Dennis at Midwestern Machinery in the 1980's in Mpls where I was a scraping contractor with my dad. Dennis arranged a scraping class at Honeywell (Alliant Tech) where he worked and I taught him to scrape the modern methods, using a carbide blade and a BIAX scraper.. He did learn to scrape from his dad who learned from my dad in the 1950's - 1960's when my Dad was a Rebuilding contractor when his dad worked at American Hoist in St. Paul, MN.

Back then they used HSS because carbide was to expensive as were diamond wheels that were the only way to sharpen carbide scraper blades, the green wheel left scratches as they were to coarse. I invited Dennis to attend your first scraping class in St. Paul. I mentored you in many machinist tricks, let you copy many of my text books, gave you a copy of my DVD on how to scrape. and I suspect I introduced you to this Forum when we me talking on Practical Machinist forum when you asked for info on your turret lathe. Back then I was also I was the lead moderator in this Hobby Machinist rebuilding forum. Nelson Timken the originator of Hobby Machinist asked me to be the moderator as we met on another forum. I never mentioned using HSS to you. It may have been in the Connelly book I gave you, but again it was written in the 1950's when carbide was expensive. I used HSS steel when I was a kid and stopped using it in the 1970's. The hand scraper the OP is using is made in Germany and like Sanvik it comes with a Carbide blade. Anyone learning to scrape in the 2020's uses Carbide as it makes scraping cast iron a dream. Using HSS makes a beginner spend 1/2 the time sharpening the dull blade. Today one can buy a diamond lapping wheel for $15.00 on ebay and make a sharpening lap it attaches too. It's silly in my opinion to use a sharpening stone to sharpen HSS today. I now have taught scraping for over 45 years and have over 40,000 students with students around the globe. One can find how to make a lapping machine by Googling "Glendo Lap alternative. To the members I am the only Professional Machine Rebuilder who writes in this Forum who has been doing it for more then 56 years. We were paid to rebuild machinery, it wasn't a hobby, I helped my Dad when I was aa 12 yr old kid in our basement, helped during summer vacation and started working full time in 1971. I am now 72 and there are only a few people who can teach scraping who are members here and in my opinion there is no one else from MN is one. There are 3 or 4 in California who I can think of.
 
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I can get a deal for members who want a copy of the Edward Connelly book "Machine Tool Reconditioning" The publisher made a small error and printed some books with some missing pages. I am friends with the Copyright owner and he will sell me those books to me for a deal, I can photo copy the missing pages and insert them in the books. I also sell the good book with no missing pages. If you want to buy them, Private message me.
 
@Richard King 2,
I may be wrong, but I hopefully was reading @Ultradog MN's post in the context of using HSS, handwheels, etc and before carbide and DROs on a lathe, AND ALSO hand scraping before power scraping. I think there is some merit to that much, but I'm not going to try hand scraping with HSS. At some point you go back to the point of rubbing sticks together to heat your cave (house). I'm not that old, but I have to agree with your point and would like to actually use the machines I'm rebuilding so making reasonable progress is important.

I see a lot of YouTube videos where a machine is rebuilt end-to-end and then put into service. I'm taking a bit different approach and "tinkering". I get machines useable, then decide what I want to improve. Fix one thing and then use it again for a while. Then fix/improve/rebuild the next thing. I've fixed/repaired clutches, bearings/bushings, gears, motors and electronics, VFDs. And learned basic machinist ideas of accuracy, measurement. Want to add scraping and way improvement to my skillset. There is some level of foundation that is helpful to build skills upon.

I'll find something to measure my hand scraper's radius against. Guess a soda can rim may be in the right ballpark. Pictures when I get a chance.
 
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FOMOGO said:
I always wince at the the price too, but right tool for the job and all that. I have enough jobs for one to justify it, but still hoping to trip over one for a low ball price. Mike
Click to expand...
Mike,
Sounds like we're in similar predicaments, although I suspect you have a little more skill in this area than I do. But I'm learning, and having fun at it.
 
Matt Critcherly one of my many class students in Madison WI made a simple sheet to measure the blade radius. He used a draftsman compass and drew circles on 1/4" graph paper and then laminated it. Another friend uses tin cans like you said....soup can, tunafish can and a coffee can. :)

There used to be a guy selling Sanvik Carbide blades on eBay for $25.00 each. I didn't see him anymore.

I found these.
www.ebay.com

Carbide Machinist Scraper Inserts Cast Iron Scraping Blades 20x30mm, 30x30mm | eBay

The 20x30x2mm inserts are good for general to finish scraping. The inserts will still need sharpening and honing, this can be done with a regular set of aluminium oxide wheels, but for the best results finishing should be done with a diamond wheel and/or hone.
www.ebay.com

You can use a diamond cut off wheel to make a smaller blade

www.ebay.com

Tungsten Carbide Scraper Blades 2.5"/65mm (2 Pack) fits Harris/Axus/ProDec tools | eBay

Pictures show 3 of the products that these blades are designed to fit : Harris, ProDec & Axus Decor. Final 3 pictures show our blades in a ProDec scraper, to show the extra width of our blades. Harris Contractor scraper (Model No. 3670).
www.ebay.com
 
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It will be my honor to help you learn to scrape Rabler as I have several members here on Hobby Machinist I have taught to scrape. I will be driving out to Mechanicsburg, PA in the upcoming months to teach a class for DIPEC (US military machine rebuilding depot) to another class of their Apprentices. I have taught all there Journeymen to scrape over the last 30 years) and I can swing by your shop in Indiana to show you. You can buy me dinner .. :)

 
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