Thorp Air Command - T18.net

Basic metal building questions

I guess I will show my ignorance by asking a series of maybe simple or OCD questions.

My Throp project starting with damages outer wing panels for a convertible wing (S-18) has been languishing for several years. Some health challenges, work commitments, family commitments and two daughters getting married etc. Anyhow, I am nearing semi-retirement and finally trying to revive the project. Oshkosh 23 has certainly helped to reinvigorate me.

Anyhow I thought I’d just ask these questions in one fell swoop. No need to “quote” this original post, probably the simplest way is to simply provide your answer to each number.

Cleco Questions:
1) Are the 1/8” (Copper) and 3/32” (silver) clecos really the fractional size, or are they truly #30 & #40 respectively?

2)If truly numbered rather than fractional, will the slightly smaller fractional pilot hole still allow the appropriate #’d cleco to work? For example, will a #30 cleco easily fit into a 1/8” drilled hole?

Drill bit, pilot holes, reamer & process for hole prep prior to rivet questions:

3) I understand that a standard drill bit whether fractional or numbered really does NOT leave a circular round hole. Rather they are distorted and oval-ish shape. Do all the holes drilled need to be reamed out to the proper and truly round numbered rivet size? Or is the deformation from driving the rivet “fill” the odd shaped hole and it is nothing to be concerned about?

4) What is the best, proper or acceptable process for drilling initial hole and installing a rivet?
4A) Can I simply drill a #30 hole with a drill bit (without smaller pilot), deburr and install the #30 rivet?

4B) Or should there be a 1/8” pilot followed by a #30 reamer and then install the #30 rivet?

4C) Or should there be a 3/32” pilot, then expanded to 1/8” or #30 and then #30 reamer followed by the rivet?

Thanks

Stick with the number drill bits. Clecos fit number holes. Drill #40 first. The drill out to #30 will take care of any slightly misaligned holes. I have some #40 to #30 reamers that I was given by an aircraft manufacturer worker, but a sharp #30 will work just fine.

_________________
Bob Highley
N711SH
SN 835
KLAL

Thanks Bob.

I was hoping I didn't need to do a whole additional framing operation step!

Does one have to debur the pilot holes?

Deburr final holes before dimpling.

_________________
Bob Highley
N711SH
SN 835
KLAL

I took the EAA Sportair 2 day workshop class , "Sheet Metal Basics." Best 2 days I spent helping me build my S-18 . Taught me all the basics , from drilling , bucking rivets and bending sheet metal . I highly recommend the course .

RB
NX115RX

Thanks bob.

Also Rich, I just looked and currently there are no upcoming dates for sport air for sheet metal. At least that I could find. The last just occurred prior to Airventure. But I will keep an eye out. I don't think they are cheap, but as you say may be worth the price of education.