Plywood Speargun Build

[Mike-Chi-D]

90cm Speargun build in Plywood as a prototype before making one in a fancier wood (although plan to use it extensively until I have time to start the next).

18mm Marine ply, usually quite expensive, but managed to get a 2ft x 4ft section for £20 as it was an odd piece at the yard. Seems good quality with a good number of laminates and minimal voids and blunted jigsaw blades very quickly!

Knocked the rough design up on AutoCad and transfered to the ply.

Ermes reverse trigger mechanism, 10mm x 8mm groove routed out from each sides for rail

Two halves joined using west epoxy and some fibreglass

Handle/trigger guard cut out of 1 x thickness of plywood and attached

Extensive sanding/profiling with belt sander

Rail made from epoxy and graphite by using a spear as the male part of the mould, same method as detailed in my thread here:

https://forums.deeperblue.com/threads/adding-rail-to-speargun.103598/

Spear I used to create the rail (belongs to the 75cm gun)

Some balsa stuck onto the sides of the handle and profiled.

Next steps:
1. Buy spear/bands/misc hardware and dry fit.
2. Final filleting and sanding.
3. epoxy coating.
4. Fish destruction.

 

[scallywag]

View attachment 41064

 

[scallywag]

Gotta love ply!

 

[Mike-Chi-D]

Very nice!

What did you use for the Camo effect?

How do you find it buoyancy wise?

 

[scallywag]

The handle's got about 130g of lead in it giving a slow sink with the spear in and buoyant with spear out. The stripes are made from a can of black spray paint!

 

[Mike-Chi-D]

Progress:

Added some ply to the bottom of the shaft to stiffen it up, seemed to be a bit flexy without

band hole drilled (16mm dia for a 18mm band), string to mark out the band grooves.

band grooves done with a power file and sandpaper

line guide/keeper

drilled holes for fittings, filled with epoxy then drilled out and tapped.

1st coat of epoxy then sanded back

 

[Mike-Chi-D]

Seccond coat of epoxy

Bands cut & wishbone tied

 

[Mike-Chi-D]

Final photoshoot!

 

[scallywag]

Looking great Mike. You may need to knock the edges off of the spear notch or your wishbone won't last long. When's the maden voyage?

 

[Mike-Chi-D]

Cheers,
Thanks again for the trigger - might need another soon, feel like making another already!

I did think the spear notch seems very sharp, what would you use, a fine file?

Hopefully will be able to get out soon down Plymouth way.

 

[foxfish]

Those triggers are easy to fit but I had to cut back the line release & polish the edges on the one I fitted.

 

[scallywag]

Yes a needle file. If you want a nice polish you can use some cord and grinding paste. The edges of the line release can be a little sharp but it's a small price to pay for compact dimentions and ease of installation. Gun buliding is very addictive!

 

[Sanchaz]

Hello scallywag. Nice gun and good work!
How accurate is with this gun? Shaft without sharksin, this is not a problem? Thank you for your work! It was very useful for me.