Scraping Class

First Some basic tools:

A hand scraper, which is essentially a flat bar with a beveled radius on one end and a handle on the other. You can see some scrapers below, and the end would look similar to the end you see on the power scraper below. The other tools we used were a couple of surface plates, an angle block, a diamond grinder, and a diamond charged lapping wheel. I wasn't familiar, well with much of anything, but the lapping wheel is simply a steel wheel that you add an extremely fine diamond charged paste ( we're talking microns here). This produces a mirror fnish on even a hard surface like carbide.


The surface plates are the "masters". These are covered with ink, the the workpiece you are scraping is laid on this "blued" master. When the workpiece is removed any blue on the workpiece represents a high spot. You scrape of the high spots and do it again, and again, and again,... We use dial indicator to get 2 side parallel and the angle block to check for perpindicularity.Lapping wheel and grinder
The first pass. Now blue yet, this just roughs up the surface and preps it to receive the first bluing.

flashh to show the scrapes. BTW this was my first attempt, so anybody who knows this is bad.... keep it to yourself ;)
first cycle: notice that only 3 or 4 spots touched because it is so far from flat.
In this one I scraped the tops of the high spots ( only 4) and did it again. You can see how the high spots moved and changed in size. This does start to change much more rapidly once you remove the "big" high spots.
Here it is after 4 or 5 cycles of bluing and scraping.
It starts to look like galvanized steel for awhile.
This process continues until you are happy. The result is measured in "spots per inch". The number of spots per inch desired depends on the use of the workspace. Since I want to restore the ways on my mill I chose practice creating 20 spi. That leaves just enough peaks to slide on and enough valleys to hold lubricant. If you were making another master, you would keep cycling. to say 150 spi or more. By the way this block is "flat" NOT "smooth", but is also more smooth than it looks because of the camera flash.



Here is a surface plate that one of the guys(Richard) brought with him to scrape.
It was a 2 man job to place this thing on the master. Forrest Addy ( on the right) was teaching the class as well as helping Richard scrape this baby.
Forrest give a "Biax" power scraper demo.
This tip, on the power scraper, is pretty close to what you would do for a hand scraper. I'll post some more when I finish some of my own scraping.
We finished off one of the days with a trip to the American Precision Museum. Pictures to come...

Trip to Springfield, VT for a metal scraping seminar

I went to a 4 day seminar on metal scraping last week. This was all organized through the practical machinist message board. This process is exactly what it sounds like, you scrape metal. The amazing thing is that HAND scraping can create a truly flat surface that is not possible with MOST machines. In fact it the first machines had to be hand scraped to be accurate enough to produce more machines. I plan using this scraping techniques to recondition my Bridgeport mill. The estimate to do this by machine was 6k to 8 k!!! That's about 6 to 8 times what the machine cost.
Driving up route 7 / 11 from Albany looking at the top of Bromley. As I was driving through "the middle of nowhere" I was wondering how Springfield Vermont became a precision machine center, then I saw the river :)





They certainley had no fear of the bedrock washing away!

Scraping pictures to come...

Autobody practice.

A little practice on some 20 gauge. The top weld was done in a continuous(sortof) bead with 3/32 tungsten, 3/32 filler.UGLY. I also realized I had the starting amperage too high. It wasn't even starting the arc until 50 amps which would blow a hole( pin head) through the steel. This was mainly because I ground off the paint which took too much metal off, so it was way to thin. The barrel was really distorted too.

The lower one was stiched in smaller sections with 1/16th tungsten and filler, I used a wire brush to remove the paint, and set starting amperage to 5 amps. I kept alternating side to side to keep the metal as cool as possible. Still not great, but complete penetration.
(The circles are dime sized)

Up in Smoke, but progress was made...

It was a tough weekend for my Dewalt tools. The drill was my fault, a consumer level drill just isn't made for drilling 3" holes 1/4" steel. THe grinder, however, just gave up. I finished using it, and the next time I went to use it... NOTHIN? So, I bought a Milwaukee and got back to work.

Added the shelf for the Welder... While the Vikings were losing. !!!%^$#!^%$!#$
And starting fabbing up the clamp that will hold the Argon tank. ( If you look closely, I actually welded this 90 degrees out of position, doh!

And a test fit...

Getting lighter

Well, it is getting lighter...

Oops

OK, I knew this thing would way over-built, but it was material I already had. However after welding the two halves together, it went from over-built to retarded! Time to lighten the load. This could actually end up looking really good because of this. I'll cut some material out and drill some holes to lighten the heavy parts.

Putting the cart before the horse

Between the body work on the truck , redesign on the backhoe forks, and the new box scraper I plan on making for the ATV, I must have dragged my welding sh!t in and out of the garage 20 times. Time to build a welding cart that carries the welder, the tha Argon tank, the TIG torch, grounding clamps, filler metals, helmet, glasses, clamps, ... and anything else I can fit. Using a mix of old and new, this baby will be an All Terrain cart that is so over built it's not funny.



The bars in the back will be the handle for the cart , the bars up front will hold the welder at an angle that nake it easier to read the display, and there will be 1 or more drawers underneath withe side access.Oops, ran out of Argon...

Time to do a little bodywork. Hell it can't look any worse than it is...

Just throw on new rocker panels... Oops, the underbody they mount to is gone too! No prob, I'll just fab some new stuff, although it is so rusted I can't even tell what shape it is suppose to be.
After finding a large enough solid area was able to use the cross-section below to get the measurements I need.
Basically everything black, below the blue line has to be replaced in order to have something solid to mount the new rocker panels(red) .

Bucket Forks

Old truck... New forks
Once I figure out the exact mounting mechanism, I'll paint them.
Rounding off the tips left a bit of a fishmouth on the end of the forks, so I filled them with weld.

Ground smooth and almost ready for paint.

Fully welded
I kept waiting for the welds to POP!
Nothing a couple C-clamps and a few tack welds won't fix :-)

Fork wedges ready for caps.

Think there is a little stress in hot rolled steel!!!


Well, it was a rainy weekend, so I figured it was time to make the bucket forks for my backhoe. I bought some 3/16" 2x4 rectangular tube stock and went from there.