# Entering the world of scraping



## ThunderDog (Apr 17, 2017)

Going to look at a 36" straight edge.
	

		
			
		

		
	





	

		
			
		

		
	
  Seller is asking  $150, your thoughts?  Surface condition is not known.  One picture not included here shows light surface rust on the scraped surface.


----------



## rgray (Apr 17, 2017)

Bargain. Better snap that up


----------



## Ulma Doctor (Apr 17, 2017)

if you have a 36" surface plate , you can scrape it back to correct again.
you can make a trough with plastic wrap and 2x4's and insert the straightedge on some small wooden blocks (at 1/3 from both ends)
fill the trough with some evaporust and let it set for a few days to remove the oxidation
rinse and inspect
scrape or send it out for resurfacing if the straightedge is damaged


----------



## 4GSR (Apr 17, 2017)

rgray said:


> Bargain. Better snap that up


Yeah, $150 and you don't have to pay shipping.  You better snatch it up! 

Like Ulma Doctor said, soak it in Evaporust to tame the rust down.  Take a large honing stone and lightly hone the surface with mineral spirits to get all of the burrs, dings, positive metal removed.  Then you can start working on getting it straight again.


----------



## ThunderDog (Apr 17, 2017)

I'm not gonna brag, but...

$300 got me the 40" camelback which is in EXCELLENT condition, a 33" angled straight edge in Good/Excellent condition, and an 18"x 36" cast iron surface plate in EXCELLENT condition.  The camel back has a coating of residue from the wrapping.  I believe it was some type of rust inhibitor.  The detail photo shows the scraped marks are still in amazing shape and of course the brown goo still needs cleaned off.
	

		
			
		

		
	




Hopefully all the pics show up.


----------



## rgray (Apr 18, 2017)

Yah you suck!!!  Big time


----------



## rgray (Apr 18, 2017)

I've been trying to fall into one of those deals for a long time. Enjoy!!!!


----------



## Kernbigo (Apr 18, 2017)

if you know anyone with a inspection granite table use that to check it out with, that is what i used to scrape that camel backs into a granite inspection table


----------



## ThunderDog (Apr 25, 2017)

So, I've been getting things into their final resting place(pics on the way) and was wondering what is the best product to clean and care for a cast iron surface plate?  Currently, the surface plate has a coating of what looks like red lead.
I watched a few videos and did some quick searches on the topic and even checked Connelly's book for any mention of what to clean them with and came up some conflicting info.  I've read/seen ammonia, mineral spirits, Windex(window cleaner), use way oil, don't use way oil, etc. often with granite surface plates being the main topic.  But, when it comes to cleaning and long term storage of cast iron I have not found much. 
 For storage it came with a single sheet of vci paper but I'm not sure if that paper has a shelf life. Short of ordering a roll I would like to find some more of that, too.  Suggestions for any of these questions are appreciated.


----------



## ThunderDog (Apr 25, 2017)

Not sure if people are reading this, but I'll add this video for future forum members.
This video pretty much answers my question...I think.  Alcohol looks like a viable solution to clean cast iron surface plates.  I'm sure there are other options.


----------



## ThunderDog (Apr 25, 2017)

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.


----------



## Ulma Doctor (Apr 25, 2017)

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


----------



## 4GSR (Apr 25, 2017)

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!


----------



## 4GSR (Apr 25, 2017)

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


----------



## toolman_ar (Apr 27, 2017)

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


----------



## ThunderDog (Apr 27, 2017)

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.
	

		
			
		

		
	



Many passes later and starting to figure things out like stance, holding position, scrape length, pressure, etc.



Here are a couple of shots of my file with 87° negative rake.


----------



## ThunderDog (May 1, 2017)

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.



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.


----------



## fitterman1 (May 2, 2017)

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.


----------

