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Posted: 9/18/2007 11:59:31 AM EDT
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Was installing a MIAD grip on one of my lowers and while I had the trigger guard ears supported, I still managed to break one offhis 2) I imagine the receiver would have to be refinished. Any suggestions? |
I should of clarified that only about 1/2 inch of the ear actually broke off. Right now I glued it and it appears to be holding. |
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You may be able fix it. Drill and ream a .015 hole on the receiver. In the same spot on the ear, drill and ream a .017 hole. Press a 1/64 steel dowel pin into the receiver side. The idea here is to line up the parts properly with minimal clearance on the ear side. You may have to open up the ear hole to get it to line up better. A little slop is needed. Once you are able to line up the ear with the receiver, Get yourself some Locktite Black Max. It is the superglue of superglues. Apply a little to both sides. Make sure you line it up really well because you will never get it off once you use the Locktite. The good thing is, it is black so you will barely notice it. don't get it on your fingers. it sets up in seconds. good luck. |
| Man, I'm excited - I never heard of this Loctite 'Black Max' before. I can think of a lot of uses for that. As for the receiver 'ears', I'm amazed I didn't break one when assembling my first Bushmaster lower. The damn roll pin was stubborn so I just hit it harder. After finishing installing the trigger guard, I realized what could have happened and almost fell out. What do you do to avoid stressing the ears when installing the roll pin? |
| There are epoxys out there that metal powder can be added when mixed making a surface good enough to drill and tap...put on the trigger guard you want and use that type of epoxy to permanently attach..sand down when rock hard and paint flat black...its ghetto but its strong and cheap.Go to a motorcycle guy or custom bike guy they frequently weld up custom frames steel and aluminum. |
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I ended up w/ a lower in this condition. I cleaned up the broken off ear and the lower w/ acetone. Glued the ear back on w/ J-B weld. Filled the 2 holes for the trigger guard roll pin with J-B weld also. Let the J-B set up, then sand smooth. I installed a MIAD grip w/ the integrated trigger guard(doesn't need the trigger guard roll pin). It really looks good. Nice & clean w/out the roll pin holes. I'm going to use this lower for dark earth paint up. Ray |
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I'm no one special on this board but as a Colt armorer I would suggest anyone looking to swap out the trigger guard on ANY manufacturer's lower use a drill press for this operation. Set up is quick and easy offering proper support of the lower and a very controlled manner of easing pins out in a very controlled manner. It is my opinion that the "ears" are the weakest point of any manufacturer's lower. I had to learn the hard way! |
Sure was. The "fix" cost the owner of that lower many thousands of dollars of it's value. In this case it is just a cheap semi lower. I'd just epoxy the ear back on, maybe ream the pin hole a little over sized and stick it all back together. Pat 0-1-25 |
Same scenario. Except, I installed the roll pin prior to gluing with the JB Weld. Once the JB Weld set up, I sanded and refinished with DuraCoat. The repair has held up very nicely and isn't at all noticable. |
Just out of curiosity, did you let the JB weld fill in the small crack when put the two pieces together? I'm trying to picture how exactly this was done. Also, what kind of sand paper did you use to sand it down. btw, ScottRyan I saw your post the first time without you enlarging your font. Maybe you missed the part where I said I wanted to keep the colt lower. I also have a trigger setup that will not swap over to another lower due to the pin sizes |
Yes, I used the JB Weld liberally (but not too liberally) and allowed it to squeeze out when the two pieces were placed together. I used a very fine grit sandpaper to smooth everything out. There were a few hairline cracks that remained but I simply filled them in with DuraCoat, cured, sanded, and applied final coat of DuraCoat. |
Yes, I used the JB Weld liberally (but not too liberally) and allowed it to squeeze out when the two pieces were placed together. I used a very fine grit sandpaper to smooth everything out. There were a few hairline cracks that remained but I simply filled them in with DuraCoat, cured, sanded, and applied final coat of DuraCoat. |
lauerweaponry |
All that is an excuse. I read everything you posted and you don't need to be telling me about your set up because I'm 10 steps ahead of you. You can find a new Colt lower, you just have to look. With all the effort you are putting into the broken lower and wasting time posting about it on ARFCOM, you could of found a new lower by now. You could also send the lower into Colt and they will remake it. They might even do it for free or it might be $200. I would do this route. Do you realize you are spending more time and money on this lower than what the lower itself is worth? A lower in this condition is worth $25. I don't know why this concept is so hard to grasp for so many on this board. |
I am in the same situation. Here's my thread. I have a truly pre-ban PWA Commando lower, and therefore my lower is worth a lot more than the $99 one could get another lower for. Mine is at my gunsmith now, and he's searching for solutions. |
Welding is pretty much out of the question since most lowers are made from 7075-T6 alloy; the zinc in the alloy makes them unweldable. Besides the heat from welding would warp the part. Best bet for a repair is to take it to a machine shop or a gunsmith and see if they can do anything - some of those guys can really work magic. |
Ever hear of Magnetic Pulse Welding? but I digress.... |
Yes, but the process is not exactly available at the local weld shop, and as you stated, it's cost prohibitive. |
I realize some folks are crazy about Colts but it seems kinda extreme to pay an extra half a grand for a rollmark....is there somethin' special about the 6920 other than the markings? |
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Nothing like a five minute job that just goes straight to hell. Having seen the other threads on the subject, I've been VERY careful changing out triggerguards. I use a lead block for support, tho' the drill press idea sounds good. Driving roll pins into aluminium is just against the laws of nature.  Moon |
maybe not everybody has money growing out of their asses. ETA. maybe there is a simple fix that will be O.K. maybe not back to "super-great colt mil-spec" but back to functional. |
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I did the same thing with a RRA lower when it was about 2 weels old............I was trying to add a Magpul Enhanced Trigger Guard. Needless to say, it was easier for me to drive 120 miles to find an in-stock lower......then strip and reassemble on the new one.............ended up selling the broken lower to a guy who knew how to "Fix" it. Hope it worked out for him, but I was happier with a new lower. Just my .02 cents. TC. |
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All give you the $25.00 for it. But seriously 1st I would send it back to colt and let them fix or replace it. Call them and ask what they can do and how much it will cost. If you don't want to do that find someone who does old motorcycle restoration. Dirt bikes or Harleys and repairs Alum cylinder or cylinder head fins. Good Luck 
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If you would, please share your info on Black Max and repairing such an issue. My lower is currently at my gunsmith, but he's already said that his welder can't do the welding required. |
Sorry about your upper. The welder is probably having trouble with either the configuration, thicknes of the substrate, or the substrate itself is cast from 7075 aluminum. 6061 is much better and more common in other applications. Note to manufacturers USE 6061 T6 FROM NOW ON!!!!! That being said : It's Loctite 380 Instant Adhesive. Part Number 308050. Goood luck. IM Sent |
Wait...you are suggesting that manufacturers use a weaker alloy? In the past manufacturers have used 6061...their products were eschewed in favor of 7075. |
I just picked up my lower from Ray Parga of Del Valle Gunsmithing. As I previously reported, the welder he uses said that it was unweldable. SO, Ray drilled up through the broken piece and into the rest of the receiver, and used metal epoxy to install a spring-steel pin. He also epoxied in the trigger guard for good measure. Then he just hit it with some AlumaHyde for touch-up. You can certainly tell that something happened, but it works, it's solid, it didn't cost me an arm-and-a-leg, and my pre-ban lower is back in action!  
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