Gunsmithing: Building a black powder Cannon

[selinoid44]

Today I took a 2-3/8" piece of solid stock 10" long and bored it 7" deep with a 15/16" bit. This thing is a beast!

 

[IndyGunworks]

the bottom half is full of high temp high torque valve making compound... the top half is COVERED with red locktight. they recommend to use antisieze for the vent, but my vent is unique in the fact the liner had shifted a small bit in the mold and there was no effective way of measuring this shift. I knew my vent would be off center which is no big deal but it MAY effect the seating and the seal of the vent liner against the steel liner. So just to be sure I used the gasket compound. The locktight is because I don't want this to ever go anywhere. If it needs to come out for some strange reason then I will weld a nut to the top and the heat from the welding should be enough to free up the locktight.

304 stainless threaded rod cut off



Filed flush




Borrowed an Engine hoist and leveler from 3badkids....



This will allow my work to be much easier. I set it up at a downwards angle and use an air compressor to blow all the crap out from the casting process and from drilling the vent.





and set her back down onto a board in a way that will allow me to hone the bore.





Here is a picture of the bore as it sits right now. The hone is 240 grit and I will be using copious amounts of wd40 to lubricate. Hopefully as the hone wears down it will become closer to a 300 or 320 grit. I really hope I don't have to buy a finer grit hone to get the bore smooth enough that it wont harbor sparks and will clean out easily. Anything will be an improvement over this.

 

[1911ly]

Don't you love those Berry hone's! They work great. You are going to get a real work out though. That hone should work great on that rough surface.

 

[IndyGunworks]

I will be using an electric drill.... Shouldn't be to much of a work out.

 

[freekforge]

Shouldn't be to much of a work out.

HA! you haven't done much honing have you

 

[IndyGunworks]

HA! you haven't done much honing have you

Not of this size, but I have used the exact same setup on shotgun barrels a few dozen times.

 

[1911ly]

I have done many engine blocks. I figure thats about 2-1/2 small block Chevy's worth lol. My arm's always get sore. But it's good for you!

 

[IndyGunworks]

I have done many engine blocks. I figure thats about 2-1/2 small block Chevy's worth lol. My arm's always get sore. But it's good for you!

Think 240 grit will be smooth enough? Or should I go ahead and try and find a 500 grit as well?

 

[1911ly]

I think you for sure need to start with the 240. It will leave hash marks. You can lessen them by pulling slower. You'll want to start faster to get going. See what the finish looks like with the 240. I'd guess it will look smoother with the 500. The berry hones are aggressive. Don't stay in any one spot long. I have over size a cylinder bore to knurl a piston to fit. You can cut 3-4 thousands pretty fast. Honing stone's are way slower and easier to keep from screwing up. The berry's are way faster. You are not fitting a piston so you have more leeway I'd say.

 

[IndyGunworks]

I think you for sure need to start with the 240. It will leave hash marks. You can lessen them by pulling slower. You'll want to start faster to get going. See what the finish looks like with the 240. I'd guess it will look smoother with the 500. The berry hones are aggressive. Don't stay in any one spot long. I have over size a cylinder bore to knurl a piston to fit. You can cut 3-4 thousands pretty fast. Honing stone's are way slower and easier to keep from screwing up. The berry's are way faster. You are not fitting a piston so you have more leeway I'd say.

I could open this thing up 20 thousands and it wouldn't matter... In fact I haven't verified it yet, but when we measured to put the vent in the bore was 2 3/8th not 2 1/4 I wasn't the least bit effected by the change in bore size as it really has no bearing on my operation at this point.... I really should remeasure though because its supposed to be 2 1/4

 

[IndyGunworks]

You guys are all wrong... this was SUPER easy. Unfortunatly after about 15 minutes there isn't much of the hone left to make contact with the sides... I easily would have been happy with removing 20 thousands of material and bringing this to a shiny polished bore.... BUT, the last picture shows the surface... it feels ALOT smoother than it looks, and is a MAJOR improvement over before. We will see how happy I am with it after I get it cleaned out some.

 

[IndyGunworks]

before and afters



and again... its VERY smooth to the touch... If I want a 500 grit finish I am sure I would need one more 240 grit and a 500 grit hone... Not sure the extra 50 bucks would even be worth it... I think I am going to roll with how it is for now and we will see how hard it is to clean.

 

[1911ly]

It looks much better! Like you said. If it's hard to clean you can spent the extra$ On the extra hones. If you run fast the stones do wear fast. I admit. But they make quick work of a honing job. Are you still on task for a possible test fire this weekend?

 

[freekforge]

Looks like im late but i have finished a couple of mine with 220 grit stones. With black powder i see no real reason to polish the bore too much

 

[IndyGunworks]

Looks like im late but i have finished a couple of mine with 220 grit stones. With black powder i see no real reason to polish the bore too much

That's the way I am leaning for the moment.

 

[w_ADAM_d88]

I know you were hoping to do the first test fire this weekend... Did it happen? Or did the setbacks keep you from the testing?

 

[IndyGunworks]

No... I just didn't have enough time to get everything together like I thought I could. I did make some real progress towards that goal yesterday though.

I used ratchet straps to hold the wheels and bearings against the axle box as tight as I could so I could mark where to put the lynch pin hole in.



Close up of the bearings



I drilled the holes purposefully too close so I had to sand down the thick washer to "fit" everything together. The result is a lynch pin that is driven in with a hammer and really tightens everything up. I didn't get rid of ALL of the wobble, but enough that the thing feels stout.



My wife called the cannon the bruise maker because she kept running into the long piece of axle sticking out that you see above. After I cut it off I wrapped it up and gave it to her since she "couldn't stay away from it"... Anywho, here she is all trimmed up.



If it weren't for having help doing this, I would have been done ALOT sooner..... Photo of the "help"



And last but not least. The pvc pipe and thick dowel will be what I use to form powder charges... the foil and the plastic bag are also for the charges. the small dowel is pine, and is to replace the oak dowel I messed up. Still might try to find an oak dowel, but driving out to the west side for a 12 dollar dowel rod is out of the question for a little while.

 

[IndyGunworks]

Forgot to mention... I also got the axle box seems sanded smooth.... When I joined the pieces together with the biscuit joiner I must have been off a little on my measurements or the tool slipped because I didn't end up with a perfect seem on top, bottom, or the sides. I had to use a hacksaw on the sides and try to blend it together because the axle was in the way so I couldn't use a belt sander. I did get the trued up, but there is a small mess up I will probably fill in with more of that wood putty before paint. The top and bottom seems cleaned up real easy with a belt sander that's more than twice my age.

I am debating putting a taper on the top corners of the axle box that grows as it approaches the wheels... the goal would be to make the wheel hubs look more substantial. I am unsure if I could do this and make it look better. I don't have the proper tools for it and doubt I can have all 4 angles match closely. Still have time for that decision though.

 

[1911ly]

Great up date! I really want to see the bearing setup. I like it.

I love it went my boy helps me. Time frames go right out the window lol. But its a joy to have him interested enough to help. Get lots of pics. They will mean a lot to him later in life!

Keep up the great work. I am looking forward to the progress updates!

 

[Pete]

So cool! Looking forward to the day you shoot it.

You'll be glad you were "helped" with the project when he grows up; in fact, you will be surprised how much you were helped when somebody else is telling the story. Great project made better with the family involved.