GB Coehorn project

[Cat Whisperer]

I know you all expect me to jump in here and say paint the carriage.  The only thing that needs painted on this is the metal work. 
This oak begs to be oiled.  A Watco Danish oil in natural. 

You're right, that was my expectation -  all I can say is it appears to be a metamorphosis in behavior we're observing.

[Terry C.]

Okay, who are you and what have you done with Double D ?




As far as painting the metal, I'm seriously considering trying to cold blue the barrel first.

I have primer and paint, so if the blue doesn't come out right I can just paint over it.

[Double D]

The barrel is to big for cold blue.  When it is done it will look like the barrel was cold blued.  If you can find a pot big enough to fit it in slow rust blue it.

[Victor3]

The barrel is to big for cold blue.  When it is done it will look like the barrel was cold blued.  If you can find a pot big enough to fit it in slow rust blue it.

I don't know...I have a coehorn bbl about the same size that's cold blued and it looks nice to me. Not perfect mind you, but for what it is (A replica of an old thingy) imperfect blueing can appear to be "distressed" or "antiqued", which IMHO looks better than paint for such an item.

If it's going to be fired, any finish will be damaged somewhat in the process, and cold blueing may not look any worse than some other finishes in a short time. Very easy to touch up or re-do also...

[Rickk]

Browning would be easier and probably look more like an antique if that is the look you want.

One nice thing about browning over blueing is that browning naturally gets better over time.

[Double D]

Well, if we are talking authentic, then painting black would be correct. 

Cold blue is for touch up and not for large size full coverage article. 

[Cannonball]

I had my barrel browned and at first I thought I got jipped. It looked like plain steel, all shiny?! But over time it's darkened and really looks antiqued.
This was the day I got it. look how shiny the muzzle is.

This is recent.


Too bad I never took a good overall pic when it was new. All the crevices and stuff just darkened, no rust, just dark.

[Tropico]

Thats one HOT muzzle Cannonball .  Whats the bore on that cannon and is it from  The Canadian Cannon Company.

[Terry C.]

This oak begs to be oiled.  A Watco Danish oil in natural.

I was out of the Formby's Low Gloss Tung Oil that I used on my other projects. When I was at Lowe's this afternoon, The Watco Danish Oil was sitting next to the Formby's products.

I decided to follow your recommendation, and bought the Watco (natural) instead of the Formby's.

If the instructions are any indication, this will be easier to use than the tung oil.


I have to leave in a little while, but I hope to get the sled disassembled tomorrow night and start the finish sanding. I should be applying oil this weekend.


I'm going to leave the barrel "in the white" for now, and keep it polished and oiled. In a couple of weeks I won't have so many things happening at once and I can decide what I'm going to do with it then.

[Cannonball]

She's my gb bore. A little too much windage though (1.75 inch). Golf balls attached to a sabot made of crumpled up alluminum foil with 1 piece of electrical tape holding them together over top of 50 grains FF sends them splicing all over the place. Maybe a patch to replace the sabot would help but I'm not trying that without Cannon grade powder. Or even removing the tape and loading each piece separately... Whatever I do, I don't want to push it. 4 inch breech with a 1.75 inch bore in 12ld14 steel makes her under spec. I'd love to try a zinc or steel shot but I don't trust it. It supposedly has an 80,000 lb. tensile strength but Switlik's book taught me better than to push the Little bit of luck I have. And yes I got her from Canadian Cannon Company. The next one I buy will be up to par though. Regardless, I still love seeing her in the living room everyday.

[Terry C.]

Have you tried molding a pocket into the sabot, so that it will hold the ball centered (without tape) but fly free when the sabot exits the muzzle?


Afternoon thunderstorms have delayed my progress but the sled is now stripped and sanding has begun. I took a couple of photos just prior to disassemble.

The little guy in the foreground is my prized 'micro mortar' from Kap Pullen.

[lance]

really like that "little guy", like his big brother TOO!!!

[Cannonball]

Eliminating the tape was going to be my next experiment, but what if the range were slightly down hill? (like mine) How would you stop the projo from separating from the charge?

Like Someones video on here where he fires his swivel guns into a lake and the ball fell out the barrel just as he was about to touch it off. That was so close to a disaster. As a matter of fact, I wonder what that person does to prevent that from happening again?

Maybe a single wrap of aluminum foil to hold the two together? That may separate a little easier. We'll see. I'll post results as soon as I've tried it.

[Terry C.]

What I was thinking is that if the pocket was deep enough it might have a 'grip' on the ball sufficient to hold it in place.

But that's just speculation. I have no idea if it would actually work.

I've seen the video, and in that case the gun was up on a tripod at about shoulder level, with the muzzle depressed several degrees. And being a swivel gun it was tipped forward after loading.

I have (so far) always fired with the carriage on the ground, with the muzzle only about a foot high and always fire ball from a fouled bore. The barrel was usually either dead flat or slightly elevated, but never depressed more than a degree or so. And once rammed the elevation was not changed much, if at all, until after ignition. Under those circumstances, I've never had a problem with the ball rolling forward.

[Tropico]

I have since learned a 1/4 slice of bread works very well in the swivel. It doesn't catch fire., and it packs the ball down., It'll fly straight if you aim it straight., and have the proper  fitting ball . I don't know about aluminum., but bread doesn't even leave debris ., its good ., I use it on alot of  things now.

[Victor3]

On my 1" Parrott (Smooth bore), I ram a small wad of aluminum foil on top of the ball to hold it in position.

I made tools to form an aluminum foil sabot that's held inside (Between charge and ball) of a nitrated paper cartridge, but usually don't make these anymore. It's convenient to have them made up ahead of time, but more work than just having measured charges in film cans, loose balls and tin foil.

[Terry C.]

After sanding the individual pieces with progressively finer grits of paper on my orbital sander and a hand block, the oak was smooth and all of the grime that had accumulated over the course of the build was gone. Then it was reassembled again so that the trunnions could be properly set into their pockets. To this point I had worked on the holes a little but they were still very rough (and a little crooked) and the trunnions did not seat in them fully. The trunnion caps would bind before they pulled down against the wood. When I made the trunnion bar (mmmmm) I turned it to a diameter of 1.150" so that I could cut the holes with a 1⅛" forstner bit and have a little left to compensate for any drift or misalignment. Turns out this was a good idea. Now the trunnions are snug with the caps pulled down tight, but not so much that the barrel can't be moved for elevation adjustments.

Speaking of which, I machined a threaded insert from a ½" brass nut to fit the recess in the bottom of the brass knob scavenged from the old cutting torch (we never throw anything away) and soldered it into place. Then I mounted the knob on a piece of rod clamped in the vise, so I could work on it with a good stainless steel brush.

Now that it's no so ugly anymore, it's replaced the brass acorn nut on the stainless steel elevator screw:




I applied the Watco Danish Oil finish early yesterday morning, before breakfast (good idea), so that I could go on a ride with my friends (BAD idea). The wood was on the front porch and didn't get wet. I, on the other hand, got soaked. To the bone. Twice. Once between Fernandina Beach and Yulee, FL, and again just as I pulled back into Waycross (so close!). When i finally made it home about 6:30 pm, my leather jacket felt like it weighed fifty pounds and I poured water out of my boots.



This is probably as far as it will get for a couple of weeks. I have to attend a bike rally this weekend (cannon and mortar will be there) and then shoot my "walk the walk" match before the deadline of Sept. 10th.

[Double D]

This is a very nice piece.

When you get the barrel and hardware blackened the contrast is going to make this a very neat  looking gun.  I think that you were looking to blue his weren't you?  Have you considered powder coat in black.?

The Watco's worked great on that oak, didn't it.  Doesn't leave that shiny plastic look.

 

[Terry C.]

I went with the cold blue for now, with the notion that it would be easy to paint over the blue later. And I already had a bottle on hand. The powdercoat sounds like a good idea, I'll have to check around and see who does it locally.

The bluing actually turned out much better than I expected. I've had a little experience with it on a smaller scale, so I've already made most of the common mistakes before. This is my biggest single cold-blued piece, surpassing my 'Powderkeg' handgonne by a good margin.

I haven't had a chance to get a really good closeup photo since I blued the barrel, but here it is "on the job" (complete with BP fouling):




As for the hardware, with the exception of three brass parts on the elevator every single piece of metal on (or in) the sled is $tainle$$ $teel. It's not going to rust and I'm in no real hurry to paint over my investment. I may change my mind later, after I've gotten my money's worth.

I do plan to bead blast the trunnion caps. I was going to give them a high-polish but I think that they're too large for that and will give off a lot of glare.

I put a lot of polished brass on the field carriage for the Napoleon and even though it's beautiful (when it's clean) I paid for it with high maintenance. I won't make that mistake again.


I'm glad I took your advice on the finish, I really like the Watco Danish Oil. The tung oil is nice but a real chore to apply (long dry time, sanding between coats).