Author Topic: My seacoast mortar project  (Read 809 times)

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Offline AaronH

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My seacoast mortar project
« on: April 24, 2007, 03:19:30 PM »
Hey all, Here is a link to some pics of the progress so far. Hopefully Yahoo isn't a pain this time. You can see in the pics that glue is still drying. I also have to make some brass straps to secure the trunions to the carriage. I've got one roughed out, need to cut it to length, make some holes, add studs to the carriage and then make another. I'm 50% happy with my carriage. It looks ~ok~. Each of the beams are individual and measure about 5/16" as the crow flies. All made of some red oak I had laying around. If I get ambitious maybe I'll make one out of steel similar to the originals. Now to find something round and 3/4".

http://pg.photos.yahoo.com/ph/meatpuppeta/album?.dir=/7d26re2

Aaron

Offline intoodeep

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Re: My seacoast mortar project
« Reply #1 on: April 24, 2007, 04:37:32 PM »
AaronH,

 Here you go. I figured I'd make it easy and link the images here. Hope you don't mind. ;D






If you make it idiot proof, then, someone will make a better idiot.


Offline Rickk

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Re: My seacoast mortar project
« Reply #2 on: April 24, 2007, 04:59:31 PM »
I'm not sure what look you are going for... but,

If you are planning on painting it (black maybe?), consider coating the outside with bondo gel. It is not like bondo putty (less brittle, more durable), and not like bondo fiberglass epoxy (all runny). If troweled with a plastic auto body trowel, it would fill the cracks between the beams to make it appear as solid pieces which, if painted, would resemble steel. It would also soak into the wood and add strength. It would probably take a couple thin coats with minor sanding in between to get 100% coverage.

Is that a 50 cal?  I'm not positive... hard to tell from the picture. If it is, and you shoot live projectiles (with mild loads or they will go way too far) the recoil will not be too bad. If I am guessing wrong and it is a 1 incher, the recoil will be fairly intense and you will benefit from any added strength that an epoxy covering might give you.

With blanks and wadding (wadding not advised for full sized guns but needed for sub-caliber guns to get a bang rather than a pfffssst) the recoil will not be too bad with either caliber.

Offline Rickk

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Re: My seacoast mortar project
« Reply #3 on: April 24, 2007, 05:01:50 PM »
I just re-read and saw the "round and 3/4" part...  Then I looked more closely at the barrel.

Who made the barrel, and is it a 75 caliber?

Lee Precision makes an inexpensive .69 caliber round ball mold.

I can double check if you want, but I think that 12 gauge slugs are something like .73 . I have a mold and some cast 12 g slugs downstairs someplace. I can measure some and find the mold number if you want.

Offline Evil Dog

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Re: My seacoast mortar project
« Reply #4 on: April 24, 2007, 05:36:18 PM »
The barrel looks very Brooks.... that is who turned this one for me.  2" diameter, 35 caliber.



Evil Dog

Democracy is two wolves and a lamb voting on what to have for lunch.
Freedom is a well-armed lamb contesting that vote. - Benjamin Franklin (1759)

Offline AaronH

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Re: My seacoast mortar project
« Reply #5 on: April 24, 2007, 05:49:42 PM »
Intoo, thanks for the upload. I fought with pics a couple weeks ago that are hosted on Yahoo and never did figure it out. So, whatever you did you're a genius.

Rick, thanks for the info.  I'm not sure exactly what I am going for either other than I wanted to make something to fit this barrel into so I could play with it. This version took me about 3 hours to hack up (including ripping all of the 5/16" pieces and glue-up). Polyurethane glue is a wonderful thing. I was thinking perhaps of a good coat of fiberglass resin for strength. The bore actually measures I think .754 or there abouts. I made the barrel in my shop. It's roughly a scale of a 13" seacoast. I chose 3/4" bore only because I wanted to maximize the piece of material I had laying around. FYI, the trunnions are bolted on with 10-32 screws and the c'bores plugged to hide the bolt heads. The plugs are a bit recessed because I whacked one too many times with the hammer,  but they kinda look cool that way.

Offline Rickk

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Re: My seacoast mortar project
« Reply #6 on: April 25, 2007, 12:50:21 AM »
Nice job on the barrel. It looked like one made by one of our more popular barrel makers, but when I looked closely I noticed a couple of his  suttle  preferences missing and had to ask who made it. (Evil Dog, in case you are wondering what I mean, Micheal chamfers the fuse hole entry and always seems to stamp "US" on the top near the vent hole).

Polyurethane glue is wicked strong. Let it wait a week or so though before doing anything, as it takes at least that long to dry, and it moves (expands) while drying. It absorbs moisture from the air to dry, so keeping it in a damp spot will speed things along.

Aaron, I want to see your trunnion caps when you get them done. They are usually one of the harder things to make. I tried bending brass and had a hard time getting it to come out right. Based on advice from Tropico, I now weld or braze ears to an appropriate sized semi-circle of metal cut from a piece of steel pipe of the appropriate diameter. It is easier to get a square bend on the bases of the trunnion caps that way.