open track for wood speargun - how big?

[mariusshobo]

I am building an iroko gun that will shoot a 7mil shaft and I will varnish it. The gun will be laminated with West System 105 epoxy (+ 205 fast hardener) and I will varnish it with epoxy.

I just can not figure it out what bit to use for the open track : will 8mil diameter round bit be ok?
Amazon product
I think that the epoxy varnish will add also a layer inside the track but don't k now how thick.

About varnish, I intend to use the same West System 105 epoxy but I do not know if I can use the same hardener as for bonding, the "205 fast hardener". I've seen that West System is recommending a special hardener for coating - 207 Special Coating Hardener, but maybe there is a trick for useing the same 205 fast hardener as for bonding.
http://www.westsysteminternational....g-west-system-hardeners-fillers-and-additives

Thanks

 

[foxfish]

Cut the track, coat with epoxy, sand with wet and dry paper wraped around a 12" lenth of 7mm steel rod.
If you want a deep track then use 7.5mm rod.
Epoxy is a fantastic glue but I find polyurethane is a far better varnish, if you can justify buying a tin of two pack polyurethane marine varnish, you will find it a lot easier than using epoxy.

 

[mariusshobo]

Thanks Fox

 

[mariusshobo]

I have already laminated the stock. For how long shoud I let it to rest before start cutting the track and etc? The moisture in the wood was 8%.

 

[foxfish]

24 hours after glueing.

 

[doyenofcastle]

after planning leave it for sometimes ,mine was wrap or crook precisely after the planning but may be because of 35 mm thick of the stock

 

[mariusshobo]

planning

by planning you mean laminating?

 

[doyenofcastle]

laminate the wood then glue then plan it to get true square or rectangular piece

I laminated 4 guns each stock laminated to ( 10 mm by 6 or 7 pieces ) 2 was success as the height of the gun is 40 mm other 2 I keep planning as every time it bow up till I reach to 34 mm and still bow after return home from shop ,it may from moisture but why other 2 successful ! I marked the pieces and flip sides to follow the lamination procedure for guns for all 4 guns

try next time sipo(utile) or padauk

 

[mariusshobo]

thanks for info; I will plan it and see in a week if it bows

 

[foxfish]

The whole idea of laminating is to stop bowing, this should not happen, in fact I cant think of a single gun I have ever made that has bent in anyway.
The only thing that could make a laminated blank bend would be, wet wood drying out or dry wood absorbing moister.

 

[doyenofcastle]

I am building an iroko gun that will shoot a 7mil shaft and I will varnish it. The gun will be laminated with West System 105 epoxy (+ 205 fast hardener) and I will varnish it with epoxy.

I just can not figure it out what bit to use for the open track : will 8mil diameter round bit be ok?
Amazon product
I think that the epoxy varnish will add also a layer inside the track but don't k now how thick.

About varnish, I intend to use the same West System 105 epoxy but I do not know if I can use the same hardener as for bonding, the "205 fast hardener". I've seen that West System is recommending a special hardener for coating - 207 Special Coating Hardener, but maybe there is a trick for useing the same 205 fast hardener as for bonding.
http://www.westsysteminternational....g-west-system-hardeners-fillers-and-additives

Thanks

 

[doyenofcastle]

The whole idea of laminating is to stop bowing, this should not happen, in fact I cant think of a single gun I have ever made that has bent in anyway.
The only thing that could make a laminated blank bend would be, wet wood drying out or dry wood absorbing moister.

Hi foxfish ,

I have a question regarding the lamination (attached pictures) i want to know the cutting plan if I have a quart saw piece ,usually I got flat saw wood and I do laminated in the vertical plan but if I got quarter cut piece shall I laminate in the horizontal plan ?

 

[foxfish]

Hi, I would mix flat sawn with quarter saw if possible, I like to mix up woods and cutting patterns.
I do this for several reasons, ... strength,.... stability & because.... it looks so cool.
Guitar necks always have quarter saw wood in the vertical plane but very often have a flat sawn strip running down the middle.

 

[doyenofcastle]

Hi, I would mix flat sawn with quarter saw if possible, I like to mix up woods and cutting patterns.
I do this for several reasons, ... strength,.... stability & because.... it looks so cool.
Guitar necks always have quarter saw wood in the vertical plane but very often have a flat sawn strip running down the middle.

very nice I want to make same but for laminations arrangement if u have 2 type of wood where u put the more stable wood ? centre or out side ?

 

[foxfish]

I use this pattern quite a lot, I cut in the vertical piece once I have laminated the main stock .....

 

[mariusshobo]

I have finished the gun and it comes out really nice!

Here are some specs:
- iroko 10mm stripes laminated with epoxy;
- poliurethane paint;
- Ermes trigger mech;
- 7mil at 150cm Sporasub shaft;
- Rob Allen 55 composite reel;
- setup with 2 or 3 bands 14.4mil Sigalsub Reactive bands;
- handle : stainless steel structure + wood + epoxy puty + sand friction layer;

THANK YOU ALL FOR INFOS AND HELP!
If there are novices that need help, I will gladly answer to your questions.

And some pictures:

 

[foxfish]

Looks fantastic!

 

[doyenofcastle]

how is the band stretch ratio ?also if you need a SS muzzle let me know I do have a lot of design

 

[mariusshobo]

how is the band stretch ratio ?also if you need a SS muzzle let me know I do have a lot of design

I ve lost alot of time manufacturing the muzzle and other SS parts useing only basic tools. It would have been great to know that I can purchase ready made. Thanks for info!

 

[mariusshobo]

how is the band stretch ratio ?

I can't tell. It is as hard as I can pull (almost).