Thorp Air Command - T18.net

Supporting Owners, Builders and Pilots of the Thorp T-18 and its variants.
It is currently Thu Mar 28, 2024 3:32 am

All times are UTC - 6 hours [ DST ]




Post new topic Reply to topic  [ 6 posts ] 
Author Message
flyingfool
 Post subject: Project progress report
PostPosted: Mon Sep 05, 2016 9:00 am 
Sr. Member
Sr. Member

Joined: Wed Aug 06, 2014 11:01 am
Posts: 220
Images: 7
As some/many are aware, I'm rebuilding damaged S18 wings. I thought I'd give a progress report.

The spar cap ding has been straightened. Well 99% to maybe 99.5% straight. Not sure I can do any better. And I decided to go with a "doubler" angle extrusion. Have to order the angle from aircraft spruce. I only need like 16".

The skins are off both outer panels. I'm now in process to remove as much of the pro-seal tank sealant off the main spars. I found that the thicker the sealant was, the easier it was to remove with a putty knife. It seems to keep it soft. Where the sealant is thinner, it is dry and harder/stiffer. I found brining it out into the sun to heat up some helped soften it.

I'm not sure how "clean" I need to get with the sealant removal. Does anyone know if it is OK to just reapply over the old sealant, or do I have to pre-treat it or have to get to bare metal to get solid adhesion?

I think I will be able to salvage the root rib on each outer panel. This will save a lot of work since the bell cranks and stiffeners are already in place. I am able to get at the edge flange of the rib to reasonably mark and match and transfer the existing holes in the ribs and onto the new wing skins I will have to order. Pretty much the rest of the ribs both nose and main ribs I think I will replace with new. Simply to make installing the new skins easier. Having only to match the locations of the rivets/dimples for the spar location.

Question: a few locations when I removed the rivets buggered up the hole a bit oversize. Other than looks, is there any problem with installing a 3/16" rivet in a few locations on the rib flange?

I know they sell an "oops" rivet for #40 rivets where you can insert a #30 shank with the small #40 head. Does anyone know if the make a 3/16 shank with a #30 head? That would be about perfect for those oversized holes.

I could try to post pictures, but they are not very entertaining.


Top
 Profile Personal album  
 
bfinney
PostPosted: Mon Sep 05, 2016 12:35 pm 
Sr. Member
Sr. Member
User avatar

Joined: Thu Oct 22, 2009 2:24 pm
Posts: 501
Images: 6
Location: Yelm, WA USA
B&B Aircraft Supply http://www.bandbaircraftsupplies.com list NAS1097AD 3, 4 ,5 & 6 oversized rivits, the only downside is they sell em in 1/4 pound lots at $3.75 each.

_________________
Bruce Finney
N18JF T-18C #262
Yelm, WA USA


Top
 Profile Personal album  
 
flyingfool
PostPosted: Mon Sep 05, 2016 5:22 pm 
Sr. Member
Sr. Member

Joined: Wed Aug 06, 2014 11:01 am
Posts: 220
Images: 7
What does "oversized " mean? Is that a full 1/16"?

With how much I will spend on this project, $3.75 is no big deal for a bag. I will buy the longest ones as I have a river cutter. I can make them shorter, but not longer!


Top
 Profile Personal album  
 
Bill Williams
PostPosted: Mon Sep 05, 2016 5:37 pm 
Rivets are sized in 1/32" ie a number 2 rivet is !/32" in diameter a 3 is 3/32 . a 4 is 4/32. a 5 is 5/32 and so on
If you drill out a 4 rivet and clean it up you will need a 5 rivet


Top
  
 
flyingfool
PostPosted: Tue Sep 06, 2016 6:11 pm 
Sr. Member
Sr. Member

Joined: Wed Aug 06, 2014 11:01 am
Posts: 220
Images: 7
Ok so now I'm confused.

I understand that standard rivet sizes are in 1/32" increments. So what does oversized rivets mean as Bfinny mentions above?

What I would like is a #5 shank with a #4 head. Is that what over sized means?


Top
 Profile Personal album  
 
Bill Williams
PostPosted: Tue Sep 06, 2016 6:35 pm 
I think Bruce used the wrong term to describe the rivet that has a 4 head with a 5 shank.
You are looking for NAS1097 rivets. These rivets have a small head when compared to a standard AN/AD rivet
Example a NAS1097AD5-8 will have a 4 head (small) with a .187 (5) shank and be 1/2" long


Top
  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 6 posts ] 

All times are UTC - 6 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 4 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron

[ Time : 0.133s | 12 Queries | GZIP : On ]