Friday, October 17, 2008

Derrick Works his Magic on a Crosman 38T, Part 6

Derrick finishes up the grips.

Spotting the holes for the palm shelf with a transfer punch.
I broke down and used a walnut colored Danish oil on the entire grip. There was some hairline checking (cracking) in the wood that I didn't notice before. By the way, the wood was air-dried as opposed to kiln-dried for anyone who takes note of such things. There's now about 6 coats of oil on the grips. I did not coat the stippled areas. Although they do pick some up around the edges as well as oil from hands. I didn't set out to artificially age the grips, but they do look more appropriate on a 38T if they appear to be 25 years old. The wood color is very reminiscent of the wood Walther used on their match guns from the late 70's and early 80's.

Drilled two holes and turned them into an oval slot. Since the grip was made for my hand it needs minimal adjustment range. If this was a production grip, the slot would have to be three times as long.

I countersunk the slot on the inside of the grip for a nut with a forestner bit. Now, I just need to attach the grips to the gun and I'm ready to shoot.

Perhaps the world's only .20 caliber match gripped Crosman 38T.

Not bad for winging it. At least now, I know which parts of the grip design need to be planned in advance. Notes to self: For the future, the palm shelf attachment to the grip should be considered FIRST. Also, consider how to lock the grips together earlier, making that connection as soon as possible to work the grips essentially as a single piece.

Thursday, October 16, 2008

Derrick Works his Magic on a Crosman 38T, Part 5

Now Derrick Starts on the palm shelf.

I still need to make the palm shelf for the match grip. A contour gauge will help fit the shelf to the right side.

It's just pressed against the grip and the grip's profile can be transferred.

The line transferred.

Back to the scroll saw.

Here's another piece for the scrap bin. I hated the look and found that the thickness was too difficult to fit to the grip. Nick would call this a prototype. I made several prototypes like this. None of them suited the grip in fit and aesthetics. I took the next few days off and got away from the project.

I tried a much thinner piece of walnut for the shelf this time. I'd started at 1/2" and was now using 1/4".

Cut out.

Went to a sanding drum chucked in the drill press. Just did some quick edge clean up.

You can just see some of the failed pieces on the work bench.

The 1/4" thick palm shelf will be too thin to attach directly to the right grip. I found a use for a piece of "prototype". Just a couple quick cuts to get it mostly rectangular. Not worth it (or safe) to use a power saw on a piece of wood this small.

I'll spare you the drum sanding pics. The block is flat on one side to attach to the bottom of the shelf. And flat at 90 degrees to attach to the gun. I'm not comfortable screwing pieces this thin together. Have you tried this Gorilla Glue stuff? It's stronger than the wood.

Quick eyeball test fit. You still think maybe I have a plan? Seriously, you must be new here.

Glue me baby

I still don't have a plan. Maybe tomorrow.

In a moment of profound forgetfulness of the recent past, some idiot decided that the shelf should be stippled to better match the grips.

I played with the contrast and light to give you a pic of how sharp the stippling texture really is.

I really liked the wax finish, but decided I'd better add a walnut Danish oil to the wood for better protection. This is only one (still wet) coat.

Wednesday, October 15, 2008

Derrick Works his Magic on a Crosman 38T, Part 4

Derrick is still coming to grips with the project...

Test fitting the two halves together.

I skipped over showing the sanding steps. Too boring. Tips: "garnet" type sandpaper is substantially better than aluminum oxide papers for wood sanding. The areas to be stippled do not need to be glass smooth. About 100 or 120 grip on those areas will be more than adequate. The non-stippled areas should be taken to about 220 grit. I don't see any real improvement going smoother.
The finish you see half-applied above is just wax from a tack cloth. I like it so much on this piece of wood, I think it's the only finish I may apply this time. I'll burnish the wax into the wood with a silicone cloth to remove the stickiness of the wax..

Stippling time. I use a Dasco Pro 7" scratch awl. Dasco model #431-0. It's heavy enough to punch the wood smartly and leave a clean impression. I've seen people use a nail and a light hammer. Too hard to juggle the grip (or stock) a nail and a hammer. A while back I also purchased a set of stippling tools that looked like a punch set with diamond-shaped serrations on the faces. All they did was smash the wood. Good stippling has a somewhat sharp texture to it. The scratch awl does needs to be re-pointed occasionally to keep it sharp.

Here goes nothing. Great care needs to be taken when working near edges as you do not want to punch through the side and have a tear out. You also don't want to punch through yourself. As I can unfortunately attest!

When working up to areas without stippling, it can be helpful to simply push the awl into the wood to create the holes and form the border.

Many, many holes make up the texture. That wax finish looks pretty good.

While I was stippling, a friend timed me at approximately four hits per second with the scratch awl. We decided that I had between 48,000 and 50,000+ punches into the wood. OCD. Carpal tunnel. Insanity. Here I come.

The right-side grip bolts to the 38T's frame. The left is attached via a metal clip to the CO2 cartridge. I'm going to lock the grips together magnetically.

test fitting

50,000 stipples......

No pics of the work. I simply spotted holes for the neodymium magnets and glued them in place. The magnets are insanely strong for their size. Now I need to remove any play in the grip halves. A couple pins should work.

Used the lathe to face off some 3/16" diameter steel rod. You can put a very square face on the rod in a single pass.

Here's the 3/16" piece that I'll make the pins from.

This looks like a good spot for a pin.

Here's another spot for a pin. Two will do it. Dilemma: How to transfer the pin holes from the right grip to the left accurately? I used a small piece of the 3/16 rod and turned a point and radius to act as a transfer punch. I lined up the left grip, pressed the grips together and the tool left a clear mark to center the pin holes.

Here's a close up of that locator. Just a simple transfer punch really.

Pins are glued into one side of the grips. They mate into the other side and have no slop in the connection. The rare earth magnets are almost too powerful. The grips don't want to come apart once attached.

I had drilled much earlier for the CO2 piercing screw hole. Extreme relief when I saw how well it lined up.

Almost home now. Just the palm shelf remains. This is clearly not a look one associates with a revolver. The ultra high-end Korth revolver served as the initial inspiration for this grip project.

I see a few spots from these pictures where I can tighten up the fit between the grip halves. Now that the pins and magnets are in place, the grip even becomes an "assembly" when it's not installed on the 38T's frame. I'll run the "assembly" across some sandpaper and close the dimensional gaps on the tops and bottoms.

More to come...