The DeeperBlue.net Gun Building Extravaganza - The Build

[Pastor]

I was hoping to discuss it here in this forum but OK. If the epoxy track is that big then what's the advantage over Derlin? At least the Derlin can float and stop the gun bending like a bimetalic strip.

[TOOmas]

Originally Posted by Pastor

I was hoping to discuss it here in this forum but OK.

sorry, i just remembered that thread and since i dont really know too much about it id thought id post it on here.

[Pastor]

No worries dude

[apneaboy]

I heard the GITS has no longer any use for his facial equipment and has grown his own gills?

[kjflyfish]

Originally Posted by foxfish

kjflyfish, just out of interest if the track was cut straight from the wood how would you finish the inside of a enclosed track designed to take a 6.5 spear?

That's a good point. Most commercially available ball-end cutters aren't sized perfectly for a 6.5mm shaft, but if you could get ahold of one in 9/32" diameter, that would be perfect. As for finishing, one coat of penetrating epoxy followed by two thin coats of epoxy will do the trick nicely. The track on my 53" black gun was cut with a 5/16" bit for a 9/32 shaft. I only put one coat of penetrating epoxy in the track, and after some hard usage, the surface of the finish has worn away. It's actually pretty cool - bare teak track on a gun coated in black epoxy.

As for epoxy vs derlin/UHMW PE - I think epoxy arose as an alternative to the more expensive plastic tracks. I think the first commercially made gun to incorporate an epoxy track was the Deathstick by Ken Jones. His customers are as loyal as they come and from what I've read, many have sold their Wongs in favor of the Deathstick. So basically, epoxy tracks have been proven. I'm not sure about the rigidity of the two, but epoxy certainly doesn't allow much flex - Steve Veros of Poseidon uses epoxy tubes in his Voodoo Stick to mitigate stock flex.

I poured an epoxy track last night on my latest creation - 63" ultra slim bluewater gun. I'll post pictures soon.

[Daryl Wong]

Aloha All,

As a tinkerer of guns for over twenty years, I've gotten to try out many different ways to incorporate a shaft in a track. Its interesting to see how gun building has developed over the years. I can remember twelve years ago having dinner with Steve Alexander and talking about building guns. Steve is considered one of the pioneers of build guns and development. We got on the subject of enclosed tracks and I had started out with wood enclosed and then gravitated to delrin tracks and then to poured epoxy tracks. Steve Alexander had been there done that many years before me and basically told me what I discovered on my own.
He said that no matter what type of enclosed track you use, it makes no difference in performance. I found that out too. Poured tracks are not new. Its been around for years. It adds no strength and neither does Delrin. In fact the epoxy tracks are more fragile and chip out easy. Delrin doesn't bond to anything so you end up having to use mechanical retention. It also has a different expansion rate to wood.
So basically most of what you see being done today is re invention of the wheel. There is a great article in one of the Hawaii Skin Diver issues that was written by Steve Alexander on the uses of epoxy and Delrin for tracks. If you can find it, it is great reading.
Hope this helps all of you that want to build guns. No sense re inventing the wheel. Or if you do, don't try to hype it up. Ask Steve Alexander..

Aloha,Daryl

[kjflyfish]

Dr. Wong,

Thanks for the insight - Let me first say that I have the utmost respect for you and it's very cool that you get on the forums and provide input. I've read excerpts by Steve Alexanders and Bill Kitto on tracks, and yes, friction/performance, etc. isn't affected at all. That's basically why I don't go for the full-length plastic tracks. The extra cost and installation trouble isn't worth it. But epoxy filled with different additives can be incredibly strong and I use it in the muzzle area to reinforce the enclosed track, that's all. I've busted a wood track once - it occurred directly along the wood grain. At least with epoxy there aren't grain weaknesses - it's all homogeneous.

Maybe I shouldn't have mentioned that part about the Deathsticks. It seems that it hit a nerve. Please know that I have only the best things to say about Wong Spearguns. I have recommended your products many times and would be proud to own one.

Cheers,

Kolt Johnson

[blaiz]

I dont think there is any bad blood here at all. It didnt sound like Mr. Wong even took thought to the comment. The fact that almost all guns are compaired to Wong Hybrids says enough.

Have we decided on a track yet? I think the GITS needs to pull some rank here settle this debate.

[foxfish]

There has been mention of cost, well we do have a budget but I can assure you that a derlin track is not an issue.
Personally I dont like the idea of trying to coat the inside of a wooden track. I just cant see how you could get a uniform finish & I definitely dont like the idea of bare wood inside the track.
A free floating derlin track is the method I have used on the last couple of guns, the tracks are trapped either end but do allow minimal movement.
The tracks I use, could also be simply affixed at one end with a countersunk s/s screw!
I would however like to see some other type of plastic used in place of derlin, I posted a link a few pages back.
Our gun is already unusual & I hope is stays that way, "all in all" I love all the input & especially the different opinions - keep them comming we will get there in the end

[glowworm]

Foxy the last gun you built had the derlin track? If so it looked the business.All my guns have enclosed tracks so i would be happy to see any but from reading this thread the derlin looks the best option.

[THE GITS]

Hello spearos

Input was al little sparse so we had to make a decision. We decided that the 4 outer laminates would be 12mm or 1/2" and the centre laminate would be 12mm at the muzzle and 20mm 3/4" at the butt. Based on this we have progressed to start the build. A last minute decision had also been made to allow the centre lamination to be parallel at 20mm from the butt to a little forward of the trigger. This would exaggerate the visual effect of the taper.

Last time we left with new purchase of the timber. What I didn't speak of was how it would be stored over the coming week. As we can see in the photographs below firstly we ripped the Purpleheart and Teak boards into 55mm wide strips (guards have been removed to show the blade).Now we took accurately cut battens and carefully stacked out timber on them as shown on top of the bench. This has permitted air to circulate freely around our timber so that it will acclimatise to the workshop conditions. To recap from last week, if our timber had been from freshly cut boards then this stage would have taken many times longer, even as much as 6 weeks with a intermediate truing session to slowly reduce the size and train the timber strips to be straight.

To proceed we need to machine our timber to the correct dimensions straight and true.

[THE GITS]

To proceed we need to machine our timber to the correct dimensions straight and true. For this we can use a surface planer and a thicknesser, I have my own basic machine but this service can be found at most lumber yards or workshops. First we must use the surface planer to flatten one face of each strip of wood, we can see this again in the photographs below (again guards have been removed for photograph). When one face of each piece is straight and true we now use the thickness planer to machine our pieces to accurate dimensions. At this stage we leave one piece of Teak at 20mm thickness and machine the other 2 and Purpleheart to 12mm.

We may now think that at this point that our surfaces are satisfactory, unfortunately this is not the case as the rotary blades of the planer leave a slight rippled surface that needs to be dressed further. To do this we use a bench plane, when set to remove a whisper thin shaving the first couple of passes over the machined timber will remove small strips that form part of the peaks of the finely rippled machined surface. When we get a long thin ribbon shaving running the whole length of the timber we are good for our gluing surface. This should only take 3 or 4 passes, when done we proceed to dress all the other surfaces of the 12mm thick timbers.

[THE GITS]

Now we must examine the centre lamination. If the taper of the lamination was uniform from muzzle to butt then we would be able to simply taper one side. Since in this instance the taper starts forward of the trigger we will have to ensure that the finished form is symmetrical and taper from both surfaces. Firstly the position of the butt was marked with pencil 50mm from the thicker end of the lamination. Then another mark was placed 200mm to mark the start of the taper. Finally a third pencil mark 975mm from the second to denote the furthest point of the muzzle. For the purpose of accuracy marking is always done from one surface, the face or edge. As our lamination at the muzzle is 12mm in thickness we need to remove 4mm from each side of the 20mm lamination. With a marking gauge a 4mm and a 16mm mark was applied to both edges at the muzzle.

Once our lamination is fully marked it can now be planed to shape. Again the bench plane was used to remove carefully the waste timber. Starting at the muzzle and slowly moving our cuts further back along the lamination the taper gradually takes form. We can examine the marks from the gauge to see how close we are getting. In the photograph below we can see how on the far side we are good but still have a little to go on the near face. On my bench I have a sliding end vice which lets me use Lignum Vitae dogs faced with beech to hold timber for tasks such as this.

[THE GITS]

Just for fun we can now take a first look at how our laminations will look. We can now see that where our taper starts that we have a matching tapered gap either side of the centre lamination. We will need to be careful with this when we glue up to make sure that the laminations are shaped symmetrically.

[THE GITS]

We can now think about glueing our laminations to create the speargun blank. Firstly we needed to address the gaps created by the lamination. There are 3 ways of doing this:

Shape each lamination to fit. This is a very difficult job
Add a tapered insert in either Teak or Purpleheart. Would destroy the effect of the taper being brought forward
Squeeze the outside laminations to close the gap. This could be achieved with hand pressure alone so was deemed the way to proceed.

We needed now to make a thin tapered strip to place under the bottom lamination when glued to provide the needed support when under pressure. This can be seen in a photograph in a future letter.

The laminations were assembled dry on the bench and a minimum number of clamps applied to examine the joins, they were perfect so we can now glue. The glue used is International epoxy resin supplied for this project by deeperblue.net member foxfish along with a large quantity of brushes and some International epoxy varnish. Thank you foxfish, I am most grateful for this donation. We shall be glueing up and clamping using my bench surface as a straight surface, the bench is regularly trued and cleaned to keep it as a reference surface. To keep glue spills from its waxed surface we use cling film to be sure of cleanliness. The bottom lamination is left in the front and the remaining laminations inverted and moved to the rear of the cling film to weigh it down. The epoxy is now measured at a ration of 4:1 very carefully and mixed thoroughly. Using a brush coat all gluing surfaces with the mixed epoxy and assemble but at this stage do not proceed to clamp for a few minutes to allow the glue to penetrate the pores of the timber. Notice in the last photograph the tapered slip to support the butt of the gun to ensure symmetry during clamping.