Author Topic: After seeing it...I had to have one... (Read 1143 times)

HotGuns · « **on:** April 12, 2005, 02:46:39 AM »

Well...I did it. After lurking and spending much time on this website, I finally registered. After reading and rereading most of the articles on black powerd cannon and mortars I thought that the beer can mortar just looked like a lot of fun to build and would be a blast to shoot. :-D

So after looking at some pictures and even printing a few off, I made a Coehorn beer can mortar. I am not new to building things...Ive been doing it since I was 15.

It just so happened that I had a 5" piece of 4140 about 8" long sittin in the shop collecting dust. Approx. 6 hours later I had a fully finished mortar. I thought about attaching the trunions with allen head capscrews, but elected to weld them on.

I may not have things exactly to scale, but I beleive that when building guns or things that go bang that too much steel is definaltey better than not enough. I built a powder chamber in it, its 1.250 dia. by 1.250 deep. Dont know the exact formula for a powder chamber but it oughta work.

Now I've got to get busy building a carriage for the thing. Any ideas or pictures ? When I can get my digital camera back from my youngest son, I'll post a picture of it. It looks pretty much like one that "Powder Keg" built, in fact it was his picture that I used for a model.

I did use a radius cutter for the radius at back though...I figured it was a lot easier since I had one. :wink:

So...whats the best design for a carriage ? I'd like to keep it authentic if its possible. I used 1.5 inch stock for the trunnion.

Cat Whisperer · « **Reply #1 on:** April 12, 2005, 06:58:23 AM »

HotGuns -

WELCOME, looking forward to the pix.

CAV Trooper · « **Reply #2 on:** April 12, 2005, 11:23:41 AM »

HotGuns,

Welcome. Sounds like you have a nice little mortar. Did you preheat the trunnions and tube before before welding them so cracks won't form?

As to the mortar bed, it's basically a big, solid block of wood that's been carved out to fit the trunnions and bottom of the tube. Usually, depending on the size of the whole thing, there's a handle in each corner so it can be moved around.

There's a bunch of pictures in various threads that show what they look like. Cohorns used in the Civil War and earlier pretty much all had beds that are similiar. The one that CU Cannon built is pretty representative.

http://www.graybeardoutdoors.com/phpbb2/viewtopic.php?t=52532

Cannon Mania also some good pictures of mortars at:

http://www.cannon-mania.com/mortars.htm

HotGuns · « **Reply #3 on:** April 17, 2005, 03:20:51 PM »

Finally... a picture of the first stage of the mortar...

the trunion caps...which I formed by making a die for 1 1/4 inch trunion

the powder chamber which is 1.25 x 1.25

lots of Breakfree on it to keep it from rusting...

I think Ive got the pics figured out...

and YES..the whole thing was preheated to 500 degrees before welding.

Now...on to the base...which is beggining to look like its going to be made of out of cabinet grade oak and laminated together for the thickeness...

Cat Whisperer · « **Reply #4 on:** April 17, 2005, 03:30:17 PM »

Even though the first two pictures were a little small, the mortar looks very good!

Smooth bending job on the trunions too!

Pick the base that YOU like. Then build another of a different design, then build another with yet a different design, then ....

CAV Trooper · « **Reply #5 on:** April 18, 2005, 09:43:21 AM »

HotGuns,

Great looking mortar! :toast: Since you're close to finishing it, the next thing you need to do is make some ammo for it. Here's how to do that:

Step 1 - Run out toyour local store and stock up on on a large quantity of 12 ounce cans of your favorite "ammo".

Step 2 - Invite one or more of your good friends over to help you empty the "ammo" cans. :gulp:

Step 3 -

For some strange reason I've never been able to get past "Step 2" but I'll figure it out one of these days. :-D :-D :-D

CU_Cannon · « **Reply #6 on:** April 18, 2005, 04:04:04 PM »

Good looking work!

Are you going to put any type of finish on the barrel or leave it plain?

HotGuns · « **Reply #7 on:** April 18, 2005, 04:18:09 PM »

That 4140 would be a constant chore to keep it shiny...that stuff loves to rust.

Im seriously thinking about either blueing it or painting it black...but the more I think of it the more Im leaning to just painting it and being done with it...

I did some work on the carriage today. I used a 6x8 peice of oak cribbing that happpend to look pretty good when I cut it up on the bandsaw. My carriage will probably be 2 inch thick solid oak.

Its coming along...

Cat Whisperer · « **Reply #8 on:** April 18, 2005, 04:27:43 PM »

It is true that 4140 rusts, as do most steels, but the design is such that with a wire bush (as on a 1/4 hp motor or electric drill) keeping up the finish isn't tough.

With any finish, oiling it after cleaning (as with hot soapy water) is a must.

If you paint it, you might want to have it sand blasted or oxide coated to provide a bonding surface for the paint.

hammer shell · « **Reply #9 on:** April 18, 2005, 05:32:50 PM »

if you decide to paint it,you might try a product called por15. its a frame paint used by car builders.it actually sticks better to rusted metal.some of the tuffest stuff i have ever seen for metal......hammer

Evil Dog · « **Reply #10 on:** April 18, 2005, 06:50:28 PM »

POR 15 ? Where do you find it?

jeeper1 · « **Reply #11 on:** April 18, 2005, 08:23:42 PM »

Paint Over Rust 15, now where did I see an ad for that recently? Darn senior moments. It's heck getting old!

hammer shell · « **Reply #12 on:** April 19, 2005, 05:57:20 AM »

heres a link to por15.its spendy but really is tuff stuff.its often used to seal the inside of rusted gas tanks on motorcycles.
as far as a rust blueing,tack of the wolf sells a product called wahkon bay rust blueing.it is formula mentioned earlyer thats nasty to work with.
but the nasty parts already been done. a friend of mine makes this product,and it works very well.i dont know that it would be correct on cannon........hammer

hammer shell · « **Reply #13 on:** April 19, 2005, 06:00:08 AM »

forgot the link,and thats track of the wolf . and i cant spell but you will get used to it.......hammer
http://www.por15.com/

CU_Cannon · « **Reply #14 on:** April 19, 2005, 05:07:23 PM »

I cold blued my golf ball mortar. I really liked the way it turned out but a few more applications would have been better. I put on about 8 coats sanding with steel wool between each one. It could have stood about 3 or 4 more. One trick that I tried that worked quite well is to wipe the barrel down with bleach first. It seamed to make the first coat much darker than without. Sanding with steel wool also helps even out the finish. Also make sure you rinse the barrel with cold water after sanding. If the barrel is warm the cold blue solution evaporates too quickly and leaves the barrel very streaky.

You should blue at least one barrel. The really look nice with an oiled oak base. You can always paint the next one. A well done paint job would take about as long as cold bluing a barrel.