Balancing first gun

[onkelhedde]

Hi
I am putting the finishing touches on my first build, have mounted all the hardware and took the gun to the pool for final balancing.
Brought liberal amounts of lead but to my surprise the gun was nose heavy.
The rear of the gun has neutral boyancy though.

What do I do now? Any suggestions?

/Henrik

 

[foxfish]

I assume you tried the gun with spear in place?
You have a couple of choices - use a slightly shorter or thinner spear or add buoyancy!
You can add extra wood to the muzzle end & reshape the whole area.

 

[onkelhedde]

Oh yes, the spear was in place and so were all the other fittings like trigger guard, bungee etc. It was basically rigged like the finished gun.
I don't think that adding wood is an option for me - it will ruin the design, so I will have to go for adding bouyancy within the current design.

I am thinking of adding cork into routed pockets on the bottom of the gun, but am not sure if I will weaken the structure too much. or???

Weired "problem" I think... most posts about balancing a gun, seem to go on weighing the gun down...

 

[foxfish]

Not at all lots of folk try to build slim guns that sink including me!

You need to find the amount of buoyancy required first - get the gun back in the water but take wood (or cork) instead of lead.
Just tape the buoyancy in place until you have the balance then you will at least have a better idea of how to solve the issue.

 

[onkelhedde]

You are right - back to the pool!

Comforting to know that it is a common problem...

Thanks for advice!

/Henrik

 

[Don Paul]

Very sleek looking form, I like that. It looks like you will have one band from the images, so barrel flex may not be a issue. I would drill a 1 '' deep hole at the butt of the gun and add lead as needed. Slight front buoyancy could be achieved by a few carefully drilled holes which can be plugged with balsa dowels and epoxy or glued in place. The spot in front of the band hole would be a great spot. If you are using SS bits at the front ( line latch? ) maybe fab
the part from Ti for a small weight savings. I use Ti quite a bit on some of my guns. If purchased from from a shop that has scrap bits it need not be expensive. Very cool build mate.

Cheers, Don Paul

 

[Tin Man]

+1 for FoxFish and Don Paul's ideas. And a couple more:

You said that it was rigged and ready to shoot, but you didn't mention bands. Bands are buoyant, and they can make a difference on such a slim gun

Maybe give it a dip in seawater first? Your gun will be more buoyant in seawater than in the pool. That usually doesn't change the balance, except that it can allow you to put more weight as close to the butt as possible, which will help lighten the nose slightly.

And lastly, consider how nose heavy was it? Everyone's tastes are different, but I actually like mine just a little nose heavy. Can you set up a target in the pool and take a few shots? Have you checked the balance of your other gun(s) to see how they compare? I guess what I am asking, is what do you mean by nose heavy? Just because it sinks nose first when dropped in the water is not necessarily a bad thing. More important is how it "feels" to you when you hold it in a firing position.

Beautiful work, by the way!

 

[blaiz]

Very clean work, and beautiful gun. I won't bother posting any advice as I think you have more than 60 or so years worth posted above.

Are you going to add a trigger guard? Might add a little weight in the butt of the gun as well.

 

[onkelhedde]

Hi all
Thanks for your kind words and advice.

The butt end of the gun has perfect neutral buoyancy it is the front end that is my problem. Even without the screw on tip (Riffe), the front is slightly heavy.

@ Don Paul: Balsa plugs could be the way to go, hadn't thought of that, and Ti as well.

@ Tin Man: The gun is rigged with a 16 mm band, maybe rigging with a 20mm will solve part of the problem.
I like the thought of adding weight to the butt to lighten the nose
And yes, I will have to take the gun to the sea, it's just that I thougth the problem was/is so severe, that I needed your guys advice right away.

My aim is near perfect neutral buoyancy.

@ blaiz : The trigger guard was in place when I did the testing.

Thanks

/Henrik

 

[spaghetti]

20mm bands are likely to determine more recoil and muzzle whip than 16mm. If the gun has a particularily slim design it will suffer from it.

Have a bottle of good wine, drink it, keep the cork, drill a slot for it near the muzzle and there you go.

I have always used wine corks when guns felt muzzle heavy.
Trouble was that then my head felt heavy as well...:friday

 

[Don Paul]

My aim is near perfect neutral buoyancy.Quote :Henrik


Before you trim the gun buoyancy and balance, you may want to consider the type of water movement you have around you during the hunt.

I have found a slightly negatively buoyant gun will sit more still in moving water, as can be found in surging inshore conditions.

A blue water drift in which the gun is held along the body and then extended
just before the shot can be trimmed to act like the ''faithful dog'' if needed.

Cheers, Don Paul

 

[Don Paul]

Here's a link for some data. http://www.corecomposites.com/balsa.cfm?family_id=2

Cheers, Don Paul

 

[onkelhedde]

Thanks Don Paul
I will follow your advice and make the gun slightly negative buoyant as my main hunting grounds are inshore/costal. It makes good sense to me.

And I must say that I feel privileged to post a problem on this forum and recieving such qualified advice from you guys.

Thank you
/Henrik

 

[Don Paul]

Thanks for the kind words mate, I am still learning as well.
All the best, Don Paul

 

[onkelhedde]

- and this is what I ended up with...

As the balancing out took more than a small plug in the front, I chose to lay in a strip of cork, and lined it with black rubber for looks.
In the handle I put in a plug of lead.
The gun is still slightly nose heavy, following the advice of Don Paul - it will be near neutral when I add another band for deeper waters and bigger fish.

/Henrik

 

[Tin Man]

Beautiful job on the cork! Can you share a little more about how you did it? I don't quite understand what you did with the rubber. Is it a glue that holds the cork in place, or just a thin stripe around the surface?

 

[Don Paul]

I love the contrast of the cork and wood and the traditional looks.
The gun is a true reflection of Danish craftsmanship, very nice.

Cheers, Don Paul

 

[onkelhedde]

Can you share a little more about how you did it?

First I routed a pocket in the barrel and cut the strip of cork to size.
Then I routed a recess in the cork and glued it in place.
Masked the barrel and cork with masking tape, filled the recess with the rubber glue and wiped it clean with my finger, dipped in dish wash.
And that's about it.

@ Don Paul. I'm glad you like the cork solution, to me it is sort of a damage control. I wanted to keep the look "maritime" and had the picture of a boat teak deck in mind. It hurt me to have to cut a finished barrel though

But thanks a lot for the kind words on my design.
I'm already looking forward to building my next gun, which will be completely different.

/Henrik