Weaponeer.net
Welcome Guest
Not a member yet? Register Now! or Login
2 members and 16 guests currently online.
Search Forums:
Site Partners

This site is Gunny Approved

 


Site Login
Username

Password

Auto Login
Add me to the active users list


Forgot password | Register

Online Users
Total Users Online: 18

We have 2 member(s), 13 spiders, 16 guest(s), and 0 anonymous users online.

Members Online:
bikergunnut, shado118


[ View Full List ]
[Based on the last 10 minutes]

The most online was 215 and occured on March 28 2013 at 11:38am.
We had 5 members, 203 guests, 0 anonymouse users, and 7 bots online at the same time.
Todays Visitors (43):

Molding plastic
Weaponeer Forums : Casting

Posted in Casting
Members Viewing Topic: None

Post New TopicPost Reply
Prev Topic :: Next Topic
Author Message
  orions_hammer

SM
SM

Joined: February 14 2008
Posts: 423
Posted: June 13 2011 at 9:47pm | IP Logged Quote orions_hammer

In my long quest to stop bubbles, I made a dangerous little pressure pot from 4" ABS sewer pipe. It consists of a flat end cap, glued to about 2 feet of pipe, glued to a FPT cleanout, with an MPT cover with a little brass air fitting threaded in.


Despite ABS being made for negligible-pressure sewer use, it actually hydrotested to 125PSI without exploding, much to my surprise! The fat spiral thread starts to leak above 50psi, but I can keep the internal pressure at 90psi without working my air compressor too hard.

Inside, I put my little AK FCG casting mold, carefully reinforced with fiberglass mesh along the weak spots:


I mixed up some of my old cans of Freeman 1080 urethane, which after sitting on my cool dark shelf for 8 months still seems to work exactly like before--except the white pigment settled out, leaving cool clear plastic! As before, I mixed in about 10% chopped glass fibers (50% chopped glass is a bit stronger, but too viscous to gravity-fill my complex mold). I vacuum-degassed the mix, poured it into the mold, degassed one final time, and then let it cure at 90psi in my new pressure pot.

Here's the resulting transparent plastic FCG set, fresh from the mold. There are a few bubbles where the reinforcing fiberglass held some air, and I think the steel inserts produce a few bubbles too, but overall there are way fewer bubbles than without the pressure cure step.


Those with sharp eyes will notice I actually used a Dremel to carve in a few places on the mold, to fatten up weak areas like the back of the hammer and side of the trigger hooks.


The resulting parts are quite pretty--they're nicely clear, and you usually can't see the cast-in fiberglass mesh, except at certain angles it glints in the light. (Word of the day: Chatoyance.) It's tough to capture on the camera!


Here are the new parts installed on my AK, where they seem to function fine. I'm trying to hold off on the live fire test until they cure for a few more days, but now I'm excited about casting again!


Assuming these parts survive for some reasonable number of shots, I'm planning on using up most of my remaining urethane resin to crank 'em out. I've basically standardized on the AK FCG for my projects lately (I have an AR lower designed using AK parts), and these are Alaska-made and weigh 85% less than steel!
Agree Disagree Funny Informative Polite/Nice/Friendly Useful Optimistic Artistic Late Bad Spelling Bad Reading Dumb


__________________
See all my builds at http://www.orions-hammer.com
  Status: Offline
View orions_hammer's Profile Search for other posts by orions_hammer
 
  orions_hammer

SM
SM

Joined: February 14 2008
Posts: 423
Posted: August 07 2011 at 1:18am | IP Logged Quote orions_hammer

The new fiberglass-reinforced hammer works reliably! The whole FCG worked for a few shots, but the (mostly unreinforced) trigger hooks broke down to little nubs after only a few shots:


I like this video capture. I've got the top cover pulled off so you can just see the top of the hammer smacking the back of the bolt. The exposure is just long enough to catch the puff of muzzle gas and blur of the bolt carrier as it starts backwards.




I put this video on YouTube:
http://www.youtube.com/watch?v=n7iHp0P69h0


I burned through a few boxes of Wolf with the all-plastic hammer, and although it's looking a little white at the firing pin impact point, it's stayed together perfectly. I think my next move is to fatten up the trigger hooks substantially, and make a new mold.
Agree x 1
Agree Disagree Funny Informative Polite/Nice/Friendly Useful Optimistic Artistic Late Bad Spelling Bad Reading Dumb


__________________
See all my builds at http://www.orions-hammer.com
  Status: Offline
View orions_hammer's Profile Search for other posts by orions_hammer
 
  midmichigun

Avatar
CPT
CPT

Joined: March 01 2008
Location: United States
Posts: 1921
Posted: August 07 2011 at 10:17pm | IP Logged Quote midmichigun

OH,

Outstanding! You almost make me want to stuff my AR mold with 'glass' and degass!

Agree Disagree Funny Informative Polite/Nice/Friendly Useful Optimistic Artistic Late Bad Spelling Bad Reading Dumb
  Status: Offline
View midmichigun's Profile Search for other posts by midmichigun
 
  Sagittarii

Avatar
2LT
2LT

Joined: January 03 2011
Location: Australia
Posts: 1186
Posted: August 08 2011 at 12:24pm | IP Logged Quote Sagittarii

The plastic used in Rotary molding may help melts at reasonable temps. Comes as pellets may have to embed stiffener rods in big sections
Agree Disagree Funny Informative Polite/Nice/Friendly Useful Optimistic Artistic Late Bad Spelling Bad Reading Dumb
  Status: Offline
View Sagittarii's Profile Search for other posts by Sagittarii
 
  garrycris

Private
Private

Joined: August 23 2012
Location: United States
Posts: 1
Posted: August 23 2012 at 11:55pm | IP Logged Quote garrycris

There are so many  manufacturers of plastic components  are available in all the world. The molding operations are augmented by comprehensive post molding processes like Ultrasonic Welding, Thermolaminating & so on..

dip coating  | dip moulding
Agree Disagree Funny Informative Polite/Nice/Friendly Useful Optimistic Artistic Late Bad Spelling Bad Reading Dumb
  Status: Offline
View garrycris's Profile Search for other posts by garrycris
 
  Sagittarii

Avatar
2LT
2LT

Joined: January 03 2011
Location: Australia
Posts: 1186
Posted: August 24 2012 at 9:36am | IP Logged Quote Sagittarii

This company makes polyurethane replicas full scale or half mold on wall plaque. They have a good range and are looking for resellers. You can buy painted or in the white cheaper to paint yourself they may if asked politely give some how to info.
Have included some pictures of their wares.

New website still transferring to it.

www.replicagunsandordinanceaustralia.com/Home.php

Old Web Site
www.ozgunworksandmilitaria.com/Home.php












Agree Disagree Funny Informative Polite/Nice/Friendly Useful Optimistic Artistic Late Bad Spelling Bad Reading Dumb
  Status: Offline
View Sagittarii's Profile Search for other posts by Sagittarii
 
  OldCoot

Avatar
1LT
1LT

Joined: February 11 2013
Location: United States
Posts: 758
Posted: August 24 2013 at 6:56pm | IP Logged Quote OldCoot

Neat thread.
Agree Disagree Funny Informative Polite/Nice/Friendly Useful Optimistic Artistic Late Bad Spelling Bad Reading Dumb
  Status: Offline
View OldCoot's Profile Search for other posts by OldCoot
 
<< Prev Topic Casting Next Topic >>

If you wish to post a reply to this topic you must first login
If you are not already registered you must first register

<< Prev Page of 10
  Post ReplyPost New Topic
Printable version Printable version

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot delete your posts in this forum
You cannot edit your posts in this forum
You cannot create polls in this forum
You cannot vote in polls in this forum
Forum Jump


This page was generated in 3.3589 seconds.