Rivnut removal
- Thread starter Big Ed
- Start date
Helo pilot
Well-known member
dremmel tool works great.
Checked the parts manual and did some googling.
The top fitting is listed as an S8-75 rivnut. A bit of digging crossmatched that to mil-spec NAS1329S0875 plain blind rivet nuts. These are steel, not aluminum, which explains the difficulty in drilling. Found this diagram for the profile.
The bottom fastener is not shown on my old Bellanca parts manual, but I found some matching photos for "plusnuts" or slotted body rivet nuts. It does not appear to be a milspec fastener. It is suitable for thinner materials than the rivnuts.
For both, looks like cutting/grinding/drilling are the options. Would like to pick a method least likely to damage the frame tabs they are set in.
For the rivnuts, I wonder if drilling from the insersion side with a carbide bit sized to match the tab hole from the insertion side would be the fastest and least traumatic. Aim to cut through the material where the face flange and barrel connect. Alternatively, use a die grinder to cut off the back side.
For the plusnuts, seems like a dremel or die grinder to cut the 4 tabs would be the fastest approach. However, it might not be necessary to remove these, since I am probably going to replace rear window brackets that they are mounted in. TBD based on discussions with the welder.
The top fitting is listed as an S8-75 rivnut. A bit of digging crossmatched that to mil-spec NAS1329S0875 plain blind rivet nuts. These are steel, not aluminum, which explains the difficulty in drilling. Found this diagram for the profile.
The bottom fastener is not shown on my old Bellanca parts manual, but I found some matching photos for "plusnuts" or slotted body rivet nuts. It does not appear to be a milspec fastener. It is suitable for thinner materials than the rivnuts.
For both, looks like cutting/grinding/drilling are the options. Would like to pick a method least likely to damage the frame tabs they are set in.
For the rivnuts, I wonder if drilling from the insersion side with a carbide bit sized to match the tab hole from the insertion side would be the fastest and least traumatic. Aim to cut through the material where the face flange and barrel connect. Alternatively, use a die grinder to cut off the back side.
For the plusnuts, seems like a dremel or die grinder to cut the 4 tabs would be the fastest approach. However, it might not be necessary to remove these, since I am probably going to replace rear window brackets that they are mounted in. TBD based on discussions with the welder.
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I would drill from the top, through the flange, then just pluck them out the bottom
Hiperbiper
Well-known member
Just treat it like any other rivet; hold the snout outside of the upset and drill the flange side with a sharp drill bit 'till the flange pops off.
That second pic ain't like anything I've encountered on a certified airplane...Home Depot yes, airplane parts no.
And yes you can powder coat over them if you put a screw thru it first to keep from filling up the threads.
Chris
That second pic ain't like anything I've encountered on a certified airplane...Home Depot yes, airplane parts no.
And yes you can powder coat over them if you put a screw thru it first to keep from filling up the threads.
Chris
Bob Turner
Well-known member
- Joined
- Apr 4, 2018
- Messages
- 4,056
Yeah, do that. Otherwise you just have to put new ones in.
i third that.
According to someone on the FB group, the new window frames use regular rivnuts, not the slotted nuts. I've got the new frames on order, so hopefully not an issue. I'll probably drill out the rivnuts and replace, just to satisfy myself that it truly was a bare frame. I'll pick up a correctly sized carbide bit to speed up the process.
what part of the window frames use rivnuts?
OK, i thought they used something else there, good to know 