Entering the world of scraping

Workbench has been modified to hide and protect the surface plate and there is even space to store the straight edge still wrapped up.
Note to self after looking at pics., remove ALL items hanging on the wall to prevent falling tools while surface plate is exposed.:eek:

Surface Plate (1).jpg Surface Plate (2).jpg Surface Plate (3).jpg Surface Plate (4).jpg
 
Hey thunderdog,
alcohol has been used for ages to clean CI plates
ammonia will work too to clean the plate.
i would consider a coating of light oil to protect the plate when not being used.
rust may be the single biggest enemy next to having an object damage the surface, that i could imagine.
if it does rust, you can scrape it back to precision again
 
A cast iron surface plate, clean with mineral spirits or paint thinner. I Like the VCI paper. I personally would not use WD-40 due to it can promote "brown" rust. If anything, coat with LPS-1 or Starrett M-1. Better yet, coat with Canolde Blue marking compound that way it is ready for service.


I didn't type fast enough, Ulma Doctor beat me to it!
 
I have a small 10 x 13 cast iron surface plate that came from a machine builder that was probably made back in the 1930's in their own foundry. I also have a 30" CI straight edge from the same machine builder. The surface plate was my spotting plate until I got my first granite rock. Haven't had a chance to check the CI plate against the granite rock. I keep it coated with bluing compound until use. I'm out of town right now, I get a chance, I'll post pictures of the C.I. plate and straight edge. Ken
 
I like your hide-a-bench!

I have a large cast iron plate, that came with a plywood top. The man I purchased the plate from was 78 years old. He told me th CI Surface Plate was his dads. There are no makers markings, but it is a great old plate.
I have cleaned it with mineral spirits, and to remove canode 2244, windex. When not in use, I apply some way oil with a rag and put the top on.

Good score!

toolman_ar
 
Well I can only read so much before I just have to dive into it! I don't own any diamond grinding wheel or silicon carbide wheels, so no carbide scraping for now. Just a good old file.
I present my first scraping session.
The very first pass just after my initial bluing complete with probably really bad form and terribly bad technique.20170427_194639.jpg
Many passes later and starting to figure things out like stance, holding position, scrape length, pressure, etc.
20170427_223243.jpg

Here are a couple of shots of my file with 87° negative rake.
20170427_223502.jpg 20170427_223549.jpg
 
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Continuing my first scraping. Thoughts? I'm trying to use a very thin coat of Prussian blue does my application look about right? FYI, the angle and glare makes it look like I'm scraping perpendicular to the edge. That is not the case, as I'm scraping at an angle to all edges being mindful to not roll the edge.
20170501_225218.jpg

I'm still using a plain file, which I'm beginning to really want the carbide tip. After several scraping sessions I realize what I was doing wrong after revisiting Connelly's book. Specifically section 11.6 regarding stabilizing the work was extremely beneficial. It's true that Connelly's book is boring UNTIL that moment you've tried to scrape for an hour or two and then realize that the parts you glazed over is where you want to read the most and suddenly can't get enough information from it.

Carbide arrived from MSC. Going to go pick up another treadmill this weekend to use the variable speed motor as a slow speed grinder. I read on another forum that the green compound is good for carbide. Still need to order a diamond wheel and fab up a way to put it on the treadmill motor. Let the fun continue.
 
Looks like you're doing fine. I like to put a dose of blue on the surface plate quite thin and even.
After numerous rubbings it thins out and you start to get a much better picture of high spots which is what your going to focus on. Love the gear you picked up, I'm jealous.
 
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