Home Tournaments Calendar Weather Merchandise Sponsors

Go Back   Spearboard.com - The World's Largest Spearfishing Diving Boating Social Media Forum > Spearfishing Gear > All About Guns

All About Guns What's your weapon of choice, and why? Discuss the beloved speargun here!

Reply
 
Thread Tools Rate Thread Display Modes
Old 11-07-2020, 04:22 PM   #16
JameyK
Registered User
 
Join Date: Feb 2008
Posts: 145
Re: Gun Build: in progress

Back at work on the gun. Some of what I did was productive, but it keeps feeling like 2 steps forward 1 step back.

I started the process of removing material on the gun to make the open track shallower. My plan was to route down to the depth I want along each side of the track, and then put the gun on its side and remove the rest of the material with a flush cut bit, letting the bearing run in the track I had just routed. Im only taking down the stock forward of the trigger pocket. The first pass went great and I adjusted the router table till I was happy with the depth of track, and recut the same pass again. When I went to make the same pass on the other side of the track I did not triple check my blade placement. The fence was off by just a hair, so it left a micro thin piece of the epoxy track uncut along the shaft groove. The issue was that in some places the blade chipped away the excess material, leaving an ugly chipped edge to spear track. Functionally It wouldn't effect the shaft, but I wanted it to be as close to perfect as possible. I decided I could sacrifice another 1/16 of track depth to remove most of the chips.

Well I removed the addition material and not only did it not fix the problem (It re chipped), but it revealed an extensive area of epoxy bubbles along the wood. So I decided to take the time and try to fix it.
Attached Thumbnails
Click image for larger version

Name:	IMG_4899.JPG
Views:	76
Size:	54.8 KB
ID:	246270   Click image for larger version

Name:	IMG_4900.JPG
Views:	78
Size:	62.1 KB
ID:	246271   Click image for larger version

Name:	IMG_4901.JPG
Views:	75
Size:	74.0 KB
ID:	246272   Click image for larger version

Name:	IMG_4902.JPG
Views:	74
Size:	75.5 KB
ID:	246273  
JameyK is offline   Reply With Quote
Old 11-07-2020, 04:51 PM   #17
JameyK
Registered User
 
Join Date: Feb 2008
Posts: 145
Re: Gun Build: in progress

Before repairing the track I set up the router table with 5/16 core box bit again, and got everything dialed in to match the existing track on the gun so I could recut it no problem.

Then I taped everything with foil tape so I could dam up the track area just a bit so that any bubbles that don't come out with the torch, could hopefully rise to the top and be removed. Also I have a few extra inches of gun stock so I dammed the muzzle end a few inches early, so that in case my router setup got bumped or changed I had a reference.

The pour went great and torched out fine. My only worry was that my tape dam made the epoxy deep enough that I wouldn't try to route that track in one pass, so I needed to bring down the material before passing it on the table. Since I couldn't use the router table and risk moving my bit setup, I got out the palm router and 1/2" bit and removed the surface epoxy in 5 passes. It worked ok, but left a little bit of epoxy off to the side of the track. I figured I could pass it on the router table after I cut the track to clean things up before I flush cut the sides.

I cut the track on the router table, and it felt like it cut ok, but the track felt lumpy to me. I wonder if the epoxy pours had varying density possibly from different amounts of graphite?. What ever it was the result was not great so I had to cut the track again, just a hair deeper. That went great and it did not effect the lineup of the shaft with the mechanism. Whew

I looked more at the epoxy left by the palm router on either side of the track. It didn't look great, and I worried about it throwing off my flush cut, so I decided to remove a tiny amount of material using the router table to make a cleaner cut. And it removed the unwanted epoxy, but...... it reduced the track depth and revealed alot of the chips and air bubbles I had just filled. Dang. Functionally its fine,(im just back where I started) so this time Im moving on. Maybe I will fill bubbles later with putty

I flush cut the sides, and it went great. I did have some tear out at the muzzle end, but that's what those sacrificial inches are for. Also I can see that split lam growing, so I need to decide how to address that. I would love your suggestions
Attached Thumbnails
Click image for larger version

Name:	IMG_4903.JPG
Views:	82
Size:	76.0 KB
ID:	246274   Click image for larger version

Name:	IMG_4904.JPG
Views:	70
Size:	64.4 KB
ID:	246275   Click image for larger version

Name:	IMG_4905.JPG
Views:	69
Size:	67.3 KB
ID:	246276   Click image for larger version

Name:	IMG_4912.JPG
Views:	79
Size:	84.9 KB
ID:	246277   Click image for larger version

Name:	IMG_4913.JPG
Views:	77
Size:	82.2 KB
ID:	246278  

Click image for larger version

Name:	IMG_4914.JPG
Views:	78
Size:	53.0 KB
ID:	246279  
JameyK is offline   Reply With Quote
Old 11-07-2020, 05:16 PM   #18
JameyK
Registered User
 
Join Date: Feb 2008
Posts: 145
Re: Gun Build: in progress

For the handle I decided to go with a Meandros handle frame I ordered from Spear America. Its thin and the mounting plate doesn't come over your hand in the rear, so I thought it would be a good candidate for a custom high handle.

I took a grinder and cut off the rear section of the mounting plate. My plan is to mortise in that portion of the handle so that I can have a slightly higher grip. I still have 1/2" of material between the bottom of the mechanism and the handle. I was planning on removing 1/4" of that, and then the frame would recess 1/8". Now Im realizing that the front of the handle frame will extend forward of the trigger pocket. The gun is only 5/4" thick there, so removing that additional 1/4" means I have an area only 4/4" thick on a 130. Im a little worried now about raising the handle that high. I can reinforce with carbon fiber, or fiberglass, but Im not set up for vacuum bagging so everything would be hand laid.

I also need to make a decision on the trigger pull. I have XL size hands which is why I wanted to make a custom handle. I have a RA 110 tuna which has been my goto gun for 15yrs. The trigger to back of handle distance on that is 60mm. I also have a KAP 140 that I rarely use, its 69mm for that measurement. Obviously I am very used to the trigger on the RA so Im leaning that way as far as distance. What do you look for in handle to trigger distance?
Attached Thumbnails
Click image for larger version

Name:	IMG_4916.JPG
Views:	85
Size:	73.3 KB
ID:	246280   Click image for larger version

Name:	IMG_4864.JPG
Views:	81
Size:	67.4 KB
ID:	246281   Click image for larger version

Name:	IMG_4865.JPG
Views:	80
Size:	76.5 KB
ID:	246282   Click image for larger version

Name:	IMG_4866.JPG
Views:	84
Size:	76.6 KB
ID:	246283  
JameyK is offline   Reply With Quote
Old 11-09-2020, 10:56 AM   #19
Mikel_24
Registered User
 
Join Date: Nov 2016
Location: Bilbao (Spain)
Posts: 379
Re: Gun Build: in progress

If you want the absolute bubble-free epoxy pours or coats... there is no better way than de-gasifying the mixture (once throughly mixed, as with any epoxy) in a vacum.

With PU resin you need to do that uber FAST, so you need a vacum chamber, valves, etc... but with epoxy, being slow setting, you don't need to get so technical. They are not that expensive, so I suggest you go ahead and get a vacum pump for CF skinning. Once you get it, you could easily make yourself something to degass the epoxy mixtures.

I only went with the frame+handle scales route once... and I didn't quite like it. It is defnitely boomproof but adds a lot of weight and it is difficult to go with anatomic handle.

I have since made my own silicone mold for casting PU handles. I then trim to fit (height and angle of the dangle) and glue them to the stock (depending on the mech, the rearmost screw also grabs the handle). I also usually reinforce the whole handle/loading butt/trigger with a couple layers of CF (vacum setup).

Mikel

Are you plannin on symetric handle scales?
Mikel_24 is offline   Reply With Quote
Old 11-10-2020, 01:59 AM   #20
JameyK
Registered User
 
Join Date: Feb 2008
Posts: 145
Re: Gun Build: in progress

I was planning on asymmetric scales for the handle frame, so I have a custom ergonomic grip. My plan was to do flat teak scales, remove material where needed, and then build up details with Apoxie sculpt and wrap it in CF. I am definitely worried about the weight of the handle, especially combined with Apoxie sculpt.

The only other gun I built was 15yrs ago. I used a handle frame then and hated it. Way to heavy, and it made it nearly impossible to balance the gun the way I would like. I said I would never do that again, but here I am lol. This Meandros frame is much lighter than others Iíve held, so hopefully the weight is not disastrous again. Iím thinking I may add more wood volume in the reel area just to up the guns mass and buoyancy.

I have a Foodsaver, but I donít think I will be investing in a proper vacuum pump at this time. I have used them in the past, and your right the results are so nice. Especially with a pressure pot for casting. If my handle scales turn out ridiculously heavy I may make a cheap one time mold of the scales to then cast lighter PU versions
JameyK is offline   Reply With Quote
Old 11-10-2020, 03:54 AM   #21
Mikel_24
Registered User
 
Join Date: Nov 2016
Location: Bilbao (Spain)
Posts: 379
Re: Gun Build: in progress

Quote:
Originally Posted by JameyK View Post
.... If my handle scales turn out ridiculously heavy I may make a cheap one time mold of the scales to then cast lighter PU versions
I posted here the process of making a clay handle (as a pattern), then making the mold and finally casting the PU handles. So far I have cast arround a 8 handles or so in the same mold... and, go figure, all of them came out identical!

You can shoot me a PM or email and I will be glad to send you the pictures or discuss the processs.

PU cast resin is REALLY STRONG. I tried, intentionally, to break a handle that came out weird. I added too much pigment to it (attempting to make it pink, which in reality does not make much sense because I always epoxy coat them and sprinkle with salt for grip). The PU foamed like crazy!!! It bubled in the mold like a friking muffin!!

Once cured I beat the hell out of it... and nothing. Light as a feather (lots of bubbles inside) and wasn't able to even chip it. I threw it to the ground, let my 6 year old daugther smash it (she can break cannon balls with a rubber mallet)... and NOTHING.

So if this one, which is basically foam, can windstand so much... imagine what a properly cast handle can take.

I glue them using two part epoxy glue (Araldite Standar, from Ceys) and, if possible, drive one or two screws from the inside of the mech pocket, through the remaining wood and into the handle (also smeared with epoxy glue). Then I skin the handle joint area (not the whole handle) with two layers of CF (mostly for bling, but also adds strength).

Unless you bump it arround or use it as baseball bat, the handle only needs to windstand some of the recoil during the shoot (and that's why you also make a heavy wood stock to beging with). I wouldn't overthink or overbuild the handle..

Mikel
Mikel_24 is offline   Reply With Quote
Old 11-10-2020, 03:46 PM   #22
JameyK
Registered User
 
Join Date: Feb 2008
Posts: 145
Re: Gun Build: in progress

Thatís awesome to hear that itís so strong just poured as is. Do you add any filler to it or is it just straight casting resin? Also is it positively or negatively buoyant?
It might actually be simpler to make my perfect handle out of clay, and they make a quick one time mold with alginate, and cast each side separately
JameyK is offline   Reply With Quote
Old 11-11-2020, 02:12 AM   #23
doyenofcastle
Registered User
 
Join Date: Mar 2015
Posts: 440
Re: Gun Build: in progress

Handle is One of the most important part in gun ,make gun shoot accurate or miss ,absorbing recoil and not shifting to R,L, up ,down .
doyenofcastle is offline   Reply With Quote
Old 11-11-2020, 05:09 AM   #24
Mikel_24
Registered User
 
Join Date: Nov 2016
Location: Bilbao (Spain)
Posts: 379
Re: Gun Build: in progress

Quote:
Originally Posted by JameyK View Post
Thatís awesome to hear that itís so strong just poured as is. Do you add any filler to it or is it just straight casting resin? Also is it positively or negatively buoyant?
It might actually be simpler to make my perfect handle out of clay, and they make a quick one time mold with alginate, and cast each side separately
My spearguns are quite slim, so I try to save weight everywhere. Shaft and mech add plenty of weight to the gun and I need to make them neutral or positively bouyant (to be compensated later on). So I was certainly worried about the weight of the handle (that's why I don't like handle frame constructions).

At first I used Smooth On Feather Lite, which is well known in the fishing lure community because it is bouyant when cured and widely used to cast lures.

This resin is heavily filled so you have to mix both components very well separately before mixing them (and mixing again). It doesn't cure too fast you have plenty of room to mix, pour, etc.

BUT IT IS EXPENSIVE!

So I switched to another much cheaper resin which (telling by the specs sheet) is ligtly negatively bouyant when cured. I talked to the resin manufacturer and they recommended glass micro-spheres to compensate. This procedure seems to be used by fishing-lure makers as well.

My handles take 200ml of resin, so instead of using 100ml of A + 100ml of B, I just add a spoon of microspheres into each plastic cup and then fill to the 100ml line. Not technical at all but so far is working well. And they float.

I hope this helps!

For your particular use case I would still make a handle out of clay and a mold to cast them in a single piece. Then, if you go with a handle frame construction, slice it right in the middle with a bandsaw and you will get two pieces that can be epoxy glued to the frame, gaps filled with some epoxy putty and sanded to fit. If you use a table saw, chances are the thickness of the saw blade will be similar to the thickness of the handle frame... so you are golden.

If in the future you want to use one piece handles like I do, the same mold wil serve you well.

Mikel
Mikel_24 is offline   Reply With Quote
Old 11-11-2020, 08:37 AM   #25
doyenofcastle
Registered User
 
Join Date: Mar 2015
Posts: 440
Re: Gun Build: in progress

Did you try carbon fibre strap mix with epoxy for handle casting?
doyenofcastle is offline   Reply With Quote
Old 11-12-2020, 07:19 AM   #26
Mikel_24
Registered User
 
Join Date: Nov 2016
Location: Bilbao (Spain)
Posts: 379
Re: Gun Build: in progress

Quote:
Originally Posted by doyenofcastle View Post
Did you try carbon fibre strap mix with epoxy for handle casting?
No, I have never cast any epoxy. I believe that mixture you are talking about would be UBER STRONG, but also extremely expensive.

Cast PU is cheap and strong enough.

Also, structurally wise, you are better off adding reinforcement on the OUTSIDE of the shape. That's why I wrap the handle joint area (handle and stock) with CF fabric.

I think that we sometimes forget that the handle only has to windstand the recoil that it is transferred to the hand of the shooter, which is not much since the mass of the gun itself absorbs most of it.

Mikel
Mikel_24 is offline   Reply With Quote
Old 11-14-2020, 02:56 AM   #27
JameyK
Registered User
 
Join Date: Feb 2008
Posts: 145
Re: Gun Build: in progress

Iíve spent a lot of time in the last couple days just trying to decide how to approach this handle. Iíve just been sculpting clay over the frame, and then taking a grinder to the frame to make adjustments. Iím still undecided but here is what Iíve learned. An ergonomic grip is much more off center then I realized. Meaning when I line up my forearm with the stock of the gun there is much more handle material on one side of the frame than the other. Also there is much less material at the top of the grip to form a tenon with than I thought. My original plan was to mortise in the rear portion of the handle. I think this will still work, but even if it doesnít the frame still has 5 screws holding it in place.

I really wanted to use the eyelet at the base of the handle frame, but it just didnít fit my hand well so that has been removed with the grinder and I will just have to drill a hole through the rear of the gun so I have some where to clip a float line. That will work fine, but I do like my float lines attaching to the handle

I have enough Apoxie sculpt around to make a handle with that. I love how that stuff shapes but it is soo heavy. I have not found any good lightweight resins on island. I might see how light I can get epoxy using microcell. I still have lots of little tests to do
JameyK is offline   Reply With Quote
Old 11-14-2020, 04:01 AM   #28
doyenofcastle
Registered User
 
Join Date: Mar 2015
Posts: 440
Re: Gun Build: in progress

Quote:
Originally Posted by JameyK View Post
I’ve spent a lot of time in the last couple days just trying to decide how to approach this handle. I’ve just been sculpting clay over the frame, and then taking a grinder to the frame to make adjustments. I’m still undecided but here is what I’ve learned. An ergonomic grip is much more off center then I realized. Meaning when I line up my forearm with the stock of the gun there is much more handle material on one side of the frame than the other. Also there is much less material at the top of the grip to form a tenon with than I thought. My original plan was to mortise in the rear portion of the handle. I think this will still work, but even if it doesn’t the frame still has 5 screws holding it in place.

I really wanted to use the eyelet at the base of the handle frame, but it just didn’t fit my hand well so that has been removed with the grinder and I will just have to drill a hole through the rear of the gun so I have some where to clip a float line. That will work fine, but I do like my float lines attaching to the handle

I have enough Apoxie sculpt around to make a handle with that. I love how that stuff shapes but it is soo heavy. I have not found any good lightweight resins on island. I might see how light I can get epoxy using microcell. I still have lots of little tests to do
that point very critical ,some general rules to be considered
RAK angle ,handle holding angle ,index position ,arm position illustration in the attached pictures
Attached Thumbnails
Click image for larger version

Name:	download.jpg
Views:	93
Size:	6.1 KB
ID:	246303   Click image for larger version

Name:	gun angel.jpg
Views:	84
Size:	73.3 KB
ID:	246304   Click image for larger version

Name:	Untitled2.jpg
Views:	82
Size:	123.2 KB
ID:	246305   Click image for larger version

Name:	x2.jpg
Views:	82
Size:	118.1 KB
ID:	246306  
doyenofcastle is offline   Reply With Quote
Old 11-14-2020, 12:07 PM   #29
JameyK
Registered User
 
Join Date: Feb 2008
Posts: 145
Re: Gun Build: in progress

Quote:
Originally Posted by doyenofcastle View Post
that point very critical ,some general rules to be considered
RAK angle ,handle holding angle ,index position ,arm position illustration in the attached pictures
Thanks! Those are awesome illustrations. I feel like Im on the right track shape wise I just need to reduce handle weight for the finished product. Right now I thinking about fitting a 1/4" teak handle scale on the left side and a 1/2" one on the right and then shaping apoxie sculpt over that just to reduce the amount of heavy Apoxie sculpt
JameyK is offline   Reply With Quote
Old 11-17-2020, 03:33 AM   #30
Mikel_24
Registered User
 
Join Date: Nov 2016
Location: Bilbao (Spain)
Posts: 379
Re: Gun Build: in progress

Quote:
Originally Posted by JameyK View Post
Thanks! Those are awesome illustrations. I feel like Im on the right track shape wise I just need to reduce handle weight for the finished product. Right now I thinking about fitting a 1/4" teak handle scale on the left side and a 1/2" one on the right and then shaping apoxie sculpt over that just to reduce the amount of heavy Apoxie sculpt
Jamey,

Are you going to epoxy coat the whole handle for grip? I would certainly suggest you do!

What I do to add grip to an otherwise slick surface is to give two coats of pigmented epoxy. Appply the first one, let it cure to a tacky state. Apply second coat and when it is well gelled (but still you get some stuff on your finger when you touch it) sprinkle liberaly with salt (bigger than usual grains). The grains will stick to the epoxy and partially submerge into it. Once fully cured, rinse under tap water and voila! Only the craters in the epoxy will remain. Grippy as hell! And lasts forever.

Right after sprinkling the salt over the second coat:


Final result after rinsing (glamour pictures):




So, if you are going to epoxy coat the whole thing... why instead of teak you don't use balsa wood? It will not make any diference strength wise (that's why there is a metal frame in the first place) and it will be much ligther.

Mikel
Mikel_24 is offline   Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 11:50 AM.


The World's Largest Spearfishing Diving Social Media Forum Powered by vBulletin® Version 3.8.1
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.
Copyright ©2002 - 2014 Spearboard.com