User Panel
User Panel
User Panel
|
Posted: 7/10/2013 12:39:27 PM EDT
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.
|
|
|
|
Posted: 7/10/2013 1:33:51 PM EDT
[#1]
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. |
|
|
|
Posted: 7/10/2013 1:41:42 PM EDT
[#2]
Quoted:
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. |
|
|
|
Posted: 7/10/2013 5:38:26 PM EDT
[#3]
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. |
|
|
|
Posted: 7/10/2013 6:43:43 PM EDT
[#4]
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. |
|
|
|
Posted: 7/11/2013 4:39:36 AM EDT
[#5]
Quoted:
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! |
|
|
|
Posted: 7/11/2013 5:28:19 AM EDT
[#6]
Quoted:
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. |
|
|
|
Posted: 7/11/2013 6:36:01 AM EDT
[#7]
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. |
|
|
|
Posted: 7/12/2013 4:15:08 AM EDT
[#8]
Quoted:
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. |
|
|
|
Posted: 7/22/2013 3:56:07 AM EDT
[#9]
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.
|
|
|
|
Posted: 7/22/2013 5:01:20 AM EDT
[#10]
Looks good to me.
|
|
|
|
Posted: 7/22/2013 11:02:05 AM EDT
[#11]
That's fine for a new shooter.
|
|
|
|
Posted: 7/22/2013 3:57:29 PM EDT
[#12]
Looks like minute of man to me which is more then acceptable. Good job op for posting the results.
|
|
|
|
Posted: 7/22/2013 7:57:14 PM EDT
[#13]
That lower group is what 4 or 5 inches? That's pretty good for anybody with open sights.
|
|
|
|
Posted: 7/23/2013 3:15:57 AM EDT
[#14]
Quote HistoryQuoted:
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" |
|
|
|
Posted: 7/23/2013 5:10:22 AM EDT
[#15]
Quote HistoryQuoted:
At its widest point, center to center, it's 2 5/8" Quote HistoryQuoted:
Quoted:
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. |
|
|
|
Posted: 7/23/2013 5:41:50 AM EDT
[#16]
Quote HistoryQuoted:
That lower group is what 4 or 5 inches? That's pretty good for anybody with open sights. For sure! Good job! |
|
|
|
Posted: 7/24/2013 6:58:39 AM EDT
[#17]
hey KonsKripteD .............. .the modification Looks very interesting.
What did you use for aperture piece? how large is the aperture hole? |
|
|
|
Posted: 7/24/2013 8:18:57 AM EDT
[#18]
Quote HistoryQuoted:
hey KonsKripteD .............. .the modification Looks very interesting.
What did you use for aperture piece? how large is the aperture hole? I used a 1/4" aluminum screw spacer. The OD is 1/4" and the hole is .115". |
|
|
|
Posted: 7/24/2013 12:41:48 PM EDT
[#19]
thanks for the info. I think I may give it a try.
|
|
|
Win a FREE Membership!
Sign up for the ARFCOM weekly newsletter and be entered to win a free ARFCOM membership. One new winner* is announced every week!
You will receive an email every Friday morning featuring the latest chatter from the hottest topics, breaking news surrounding legislation, as well as exclusive deals only available to ARFCOM email subscribers.
AR15.COM is the world's largest firearm community and is a gathering place for firearm enthusiasts of all types.
From hunters and military members, to competition shooters and general firearm enthusiasts, we welcome anyone who values and respects the way of the firearm.
Subscribe to our monthly Newsletter to receive firearm news, product discounts from your favorite Industry Partners, and more.
Copyright © 1996-2024 AR15.COM LLC. All Rights Reserved.
Any use of this content without express written consent is prohibited.
AR15.Com reserves the right to overwrite or replace any affiliate, commercial, or monetizable links, posted by users, with our own.
