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How to Build a Speargun With A Neptonics Speargun Blank

How to Build a Speargun With A Neptonics Speargun Blank

If you are interested in building your own speargun, but don’t have a full workshop of woodworking tools, a speargun blank is a great option. Even if you are an experienced woodworker, the blanks are a great way to understand how a speargun works. It still affords the option of customizing a speargun exactly how you want it to be. Throughout this post we will be going over the basics of turning one of our blanks into a fully functioning speargun.


Choosing the Right Speargun Blank

The first step is to pick the right blank for the type of speargun you want to build. This really comes down to your personal preference between open tracks or enclosed tracks. Simply select your preference.


Identifying the Right Length

After picking the style speargun blank, you need to choose the length of the speargun you want to build. These blanks are 60” long, but there are only select purposes for that length speargun. Most speargun builders will determine the length speargun that suits their needs and cut the blank down to that length. Your specific dive conditions, and the species you are targeting will determine the length of speargun you will want. If you dive in a location with clear water and fish that are scared of divers, you will want a longer speargun. If you live in a place where there is limited visibility and you are shooting into confined spaces, you will likely want a shorter speargun. Once you have decided on the length you simply cut the speargun blank to that length. 


Cutting the Band Slot for Your Speargun Blank

Once the speargun blank is cut to length you can make your band slots. The band slots are where you will store your bands. These can be very simple. All you need is a drill and a drill bit. You can drill a hole for each band that you want for your speargun. Given the dimensions of the speargun body, we recommend two to three bands. Make sure to give some space between each hole for individual bands. There is a lot of force that is placed on these band holes and you need about one inch between each hole to prevent damage when the speargun trigger is pulled.

If you have a router table, you can set it up to route the band slots if you want all of your bands in one slot. Make sure that larger band slots are a solid piece, and that you tie in your speargun bands. Having a large, open band slot is an easy way to have the bands break it when loading the speargun. 


Rounding the Edges of The Speargun Blank

Our speargun blanks arrive to you as rectangles. While these can be perfectly functional spearguns as they are, they tend to look a bit better with rounded sides. If you have a router table this is a pretty easy task. You just need a round over router bit and to set it to the right height. This easily rounds over the edges of the speargun and gives it a more finished look. If you don’t have a router table, there are other options. You can use hand tools, like a chisel, if you have a great deal of patience and time.

You can hand shape your speargun to be exactly how you want it to be in this manner. The real secret to a professional looking speargun is to sand it. The sanding process for a quality speargun seems never ending. Start with coarser grits and work your way to finer grit sandpaper from there.This will slowly remove any imperfections you can see in the wood that occurred while you were building the speargun.


Finishing a Speargun Blank

The last few steps are fairly simple. You need to get the right length spear shaft for your speargun. Most spearguns require a spear that extends about 9 to 11 inches beyond the end of the speargun. Simply measure from where the spear shaft sits in the trigger mechanism to whatever distance beyond the end of the speargun, and that is the length spear shaft you need. Other than that you need to decide how you want to finish your speargun. You can use epoxy, or you can use teak oil to finish a speargun. 


Ballasting Your Speargun 

Every pice of wood is different. Some pieces of teak are dense, others are less dense. Because of that each piece of wood has to be ballasted individually. We could try and describe how to properly ballast a speargun, but the best resource we have is on the Neptonics YouTube Channel with this video. It goes over everything you will need to know to properly ballast any speargun. 
Next article How To Use A Neptonics Speargun Trigger Jig

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