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Discussion Starter #1 (Edited)
I took my hack saw to my receiver and spent some time on the belt sander. I plan to mill a mount for my holosight but for now double sided tape is for trial. Next step is to blend lines and round the edges on the top of the receiver.

Anyone have any tips on removing cast lines and orange peel surfaces without running the risk of rounding edges over that I want to keep square and making nice and flat surfaces without bumps or dips? There's a lot of surfaces that has pin holes from the casting process and I wonder how some people were able to remove or hide them.

Thanks!



 

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I took my hack saw to my receiver and spent some time on the belt sander. I plan to mill a mount for my holosight but for now double sided tape is for trial. Next step is to blend lines and round the edges on the top of the receiver.

Anyone have any tips on removing cast lines and orange peel surfaces without running the risk of rounding edges over that I want to keep square and making nice and flat surfaces without bumps or dips? There's a lot of surfaces that has pin holes from the casting process and I wonder how some people were able to remove or hide them.

Thanks!
You will find that not only is the crappy casting porous, it’s also not flat on the “flat areas”. I started with a VERY FINE single cut Nicholson file followed by block sanding.

You have a LOT of work ahead of you, but the end result is worth it.

Here’s a photo that was posted quite awhile back here of a member doing the same exact thing as you (IF the photo posts!)

6F19F1AB-A23E-45F0-87E4-BD542DBA9041.jpg
 

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Discussion Starter #4 (Edited)
These pics are after 7 hours of hand sanding. A few things I learned here, the area around the front end of the receiver has a lot of cast lines and divots that will take a while to clear up. You can't really use a sanding block on the sides of the receiver because it's not completely flat. If you look straight on the front end of the receiver there's an ever so subtle change in angle in the shape of the receiver. It kind of opens up ever so slightly.

This project is going to take a few days as I'm probably going to take a break because I need more sand paper. I am wondering what I'm going to do with that void on the top of the receiver. I've been thinking about filling it with JB weld and flattening it out to give it a finished look.

On another note, how can I post bigger pics?





 

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Discussion Starter #7 (Edited)
So a little progress report. My fingers and thumbs are numb, but saved by the discovery of a flapper sandpaper wheel. This job has taken up about 12 hours now. A friend said that a blasting cabinet would yield the same results, but I'm not too sure about that. There are some areas that I don't think I can fix as some surfaces are pocked with a million pinholes. Hardly noticeable for most but for me it's an eyesore. I think I'm mainly done though, the next step will be to mix up some JB weld and fill the void on top of the receiver. I'm taking a risk as I haven't heard anyone doing this so if anything goes wrong you'll hear it here first. After that I'll sand it down to shape and then take the receiver to my milling machine and drill a flat spot and holes for a very short picatinny rail to be mounted to the rear part of the receiver. I thought about milling out a spot for a direct Trijicon RMR mount but the PS90 is unique in that it's wider than most firearms so if the sight is low the shooter needs to incline their head more than normal for a proper sight picture. So a bit of extra height will alleviate this problem for me.









You know what’s sad any funny? All this work and effort will only be noticed by PS90 aficionados. I like it and that’s all that really matters I guess.
Below pics are for comparison with a stock PS90 Receiver.



 

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Discussion Starter #8 (Edited)
So I’m committed, let’s hope this works out! I wore down the surface to bare aluminum in large spots, used brake cleaner to degrease, leveled the receiver in a vise, and spread JB weld around like peanut butter.






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So I’m committed, let’s hope this works out! I wore down the surface to bare aluminum in large spots, used brake cleaner to degrease, leveled the receiver in a vise, and spread JB weld around like peanut butter.






Sent from my iPhone using Tapatalk
Thats a lot of JB Weld that you are going to have to sand off. I would have used the end of a flat piece of something to remove the excess before it dried.

Liquid aluminum would have been my choice of filler agent.

It's looking good though.....
 

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Discussion Starter #10 (Edited)
Ok, so the JB Weld came out alright. I wasn't expecting bubbles but then again I know nothing about epoxy other than to mix it and set it. I think it looks a lot better than previously. Not sure how I'm going to fill the divots yet. I've heard about something called Permatex liquid metal filler so I'll give that a try. After this is all said and done I think I'll a final write up on what I learned if anyone else wants to try this out. The Holosun is there for concept, the last two steps are to install a picatinny rail and Cerekote. Not sure what color though, maybe I should have it guilded or chromed lol.







 

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Discussion Starter #12
Looking great! Have you thought about attaching the sight directly to the receiver?
Thanks! Having the sight mounted directly to the receiver takes it too low. You almost have to lay your head down on the stock. I’m thinking because the PS90 has a wider than normal body. There needs to be some height and a picatinny rail in this case will add some flexibility in options.


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Discussion Starter #13 (Edited)
Ok repost,
I had a bad connection and Tapa talk doesn't do so great when it comes to posting pictures. I would have updated earlier but my buddy needed help pulling an engine out of his Subaru.
So I milled and installed the rail and I think it works out pretty well for my purposes. I'm a total novice when it comes to machining and the only experience I have is manufacturing a Titanium Suppressor (legally of course). I'm thinking about taking up some kind of gun smithing course someday. I find shaping metal is a lot of fun for me.











Now, all that's left is to fill the divots and pin holes then off to Cerakote. Not sure if I'm going for some kind of Grey, Flat Dark Earth, or plain Black.
 

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All I can say is WOW!

I saw the title and my first reaction was "Whiskey Tango Foxtrot????" but the pictures are amazing - I think you're going to have an incredibly cool gun when this is done. I'd actually be tempted to NOT coat it - might have to see the whole gun to judge, but it seems like it might look really nice with the two-tone effect going on already...
 

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Nice mill and nice work. I don't have the metal working expertise to warrant that price range for the PM Mill. So it was bottom line HF with some minor mods. Turning it into a 3 axis CNC, IF I ever find the time. Do like where you are going with this though.
 

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Discussion Starter #18 (Edited)
All I can say is WOW!

I saw the title and my first reaction was "Whiskey Tango Foxtrot????" but the pictures are amazing - I think you're going to have an incredibly cool gun when this is done. I'd actually be tempted to NOT coat it - might have to see the whole gun to judge, but it seems like it might look really nice with the two-tone effect going on already...
Thanks Solomon! I need to coat it with something though. Raw aluminum needs something to cover it for preservation and durability. The hardest part (aside from hand sanding) is deciding on what color or finish I'm going to pick.


Nice mill and nice work. I don't have the metal working expertise to warrant that price range for the PM Mill. So it was bottom line HF with some minor mods. Turning it into a 3 axis CNC, IF I ever find the time. Do like where you are going with this though.
I'd like to make my mill into a CNC but that's later on down the line. I'm very happy with the direction my modification is going. I'm learning as I go along and having fun at the same time. Things constantly change as I plan to put a custom Trijicon RMR mount instead of a picatinny rail now just to lower it to where I want it to be. Directly on the receiver is to low and on the rail is a tad high, I'm looking for juuuuuuust right. My problem is I can be a bit of a perfectionist.


As all projects like this, new challenges always come up. I thought I was smart by filling the void with a bit more JB Weld as I was afraid of Shrinkage. I don't have much experience with JB weld. Now I have to deal with swiss cheese holes.


This project is on a slight hold since work and time off has been getting in the way but I hope I'll be able to get back on it next week.
 

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I am totally impressed. The only slight drawback is the loss of the iron sights. With an eye towards minimizing I have considered removing my lump of an EOTech holo sight.
Again very well done. No half measures.
 

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I love the raw aluminum look. Black of course and I'm sure you are secure enough in your manhood for hot pink. No other colors come to mind.
 
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