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Posted: 7/10/2013 11:39:27 AM EST
Thought about going with the Krebs, but I'm a tinkerer, so I decided to make one myself. Cost me ~$10. As soon as the epoxy is fully cured, I'll sand down the excess to clean it up a little bit.



Link Posted: 7/10/2013 12:33:51 PM EST


As an engineer that works with composites and epoxies on a daily basis, I don't recommend that.

First off, epoxies aren't terribly impact resistant. I bet if you dinged that on something steel, it would pop off. Also, your mechanical bond will be all about your surface prep. Hopefully you cleaned off the finish, roughened the steel, then chemically cleaned the surface.

Also, the Tg for most ambient cure epoxies will be around 200 deg F. That part of the gun can get pretty hot, it wouldn't surprise me if you exceeded that.

I would recommend placing a small tack weld on each side of the apature instead.

Link Posted: 7/10/2013 12:41:42 PM EST
Originally Posted By mustangduckk:


As an engineer that works with composites and epoxies on a daily basis, I don't recommend that.

First off, epoxies aren't terribly impact resistant. I bet if you dinged that on something steel, it would pop off. Also, your mechanical bond will be all about your surface prep. Hopefully you cleaned off the finish, roughened the steel, then chemically cleaned the surface.

Also, the Tg for most ambient cure epoxies will be around 200 deg F. That part of the gun can get pretty hot, it wouldn't surprise me if you exceeded that.

I would recommend placing a small tack weld on each side of the apature instead.




I took off the finish where the two pieces would be bonded. I thoroughly cleaned it. This epoxy is rated for up to 550 degrees F. 4000lbs per square inch. If I had access to a welder, I would have welded.
Link Posted: 7/10/2013 4:38:26 PM EST


Their website (assuming the JB Weld in the background) says it will "withstand" 550 deg F. They don't give a modulus number or testing standards. My guess after reading the MSDS is that its some kind of novalac based epoxy. That will give you a little higher Tg around 300 deg F. It won't burst into flames after that, but the chemical crosslinking will break down.

I'm very skeptical of their claims of 4000 psi of bond strength. That is a really high number. Again, there is no test standard listed anywhere.

Link Posted: 7/10/2013 5:43:43 PM EST
Rear sight leaf does not get anywhere near 300 let alone 150 degrees F. I can easily touch mine after repeated firing. So if its cool enough to touch, heat will not be a problem. I used JB Weld several times to patch motorcycle engine side covers, including gluing on a large chunk of case around the countershaft, never had a problem.

Let us know how it turns out.
Link Posted: 7/11/2013 3:39:36 AM EST
Originally Posted By Farmer-Ted:
Rear sight leaf does not get anywhere near 300 let alone 150 degrees F. I can easily touch mine after repeated firing. So if its cool enough to touch, heat will not be a problem. I used JB Weld several times to patch motorcycle engine side covers, including gluing on a large chunk of case around the countershaft, never had a problem.

Let us know how it turns out.


Yeah, I've never experienced high temperatures on my rear sight. I'll post how it works after I sight it in next week!
Link Posted: 7/11/2013 4:28:19 AM EST
Originally Posted By Farmer-Ted:
I used JB Weld several times to patch motorcycle engine side covers,


+1

I've used it to seal small cracks in engine blocks before, I carry some every where in emergency tool kit in every rig just because of this.

If you did your prep right OP it will never come off.
Link Posted: 7/11/2013 5:36:01 AM EST
Personally I think the original sight would have been more accurate, but I understand why you did it... quicker sight picture.

let us know how it turns out, and I applaud you for just doing it.
Link Posted: 7/12/2013 3:15:08 AM EST
Originally Posted By mykrowyre:
Personally I think the original sight would have been more accurate, but I understand why you did it... quicker sight picture.

let us know how it turns out, and I applaud you for just doing it.


Thanks! Will do.
Link Posted: 7/22/2013 2:56:07 AM EST
Shot better with this sight than I ever did with the stock irons. I'm still newer to shooting, so don't give me too much shit about my 100yd groups lmao. Top group was the third group I shot yesterday, then I adjusted the front sight and really focused for the lower group. Ran out of ammo before I could get it exactly where I wanted it.

Link Posted: 7/22/2013 4:01:20 AM EST
Looks good to me.
Link Posted: 7/22/2013 10:02:05 AM EST
Link Posted: 7/22/2013 2:57:29 PM EST
Looks like minute of man to me which is more then acceptable. Good job op for posting the results.
Link Posted: 7/22/2013 6:57:14 PM EST
That lower group is what 4 or 5 inches? That's pretty good for anybody with open sights.
Link Posted: 7/23/2013 2:15:57 AM EST
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Farmer-Ted:
That lower group is what 4 or 5 inches? That's pretty good for anybody with open sights.
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At its widest point, center to center, it's 2 5/8"
Link Posted: 7/23/2013 4:10:22 AM EST
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By KonsKripteD:


At its widest point, center to center, it's 2 5/8"
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View All Quotes
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By KonsKripteD:
Originally Posted By Farmer-Ted:
That lower group is what 4 or 5 inches? That's pretty good for anybody with open sights.


At its widest point, center to center, it's 2 5/8"


Even better.
Link Posted: 7/23/2013 4:41:50 AM EST
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Farmer-Ted:
That lower group is what 4 or 5 inches? That's pretty good for anybody with open sights.
View Quote



For sure! Good job!
Link Posted: 7/24/2013 5:58:39 AM EST
hey KonsKripteD .............. .the modification Looks very interesting.
What did you use for aperture piece?
how large is the aperture hole?

Link Posted: 7/24/2013 7:18:57 AM EST
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By theprofessor:
hey KonsKripteD .............. .the modification Looks very interesting.
What did you use for aperture piece?
how large is the aperture hole?

View Quote


I used a 1/4" aluminum screw spacer. The OD is 1/4" and the hole is .115".
Link Posted: 7/24/2013 11:41:48 AM EST
[Last Edit: 7/26/2013 1:33:21 PM EST by theprofessor]
thanks for the info. I think I may give it a try.
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