Follow us on Twitter Follow us on FaceBook Kitplanes Videos Get RSS Feed
 

Shop Talk

October 2017 Issue




Plane and Simple

Removing blind rivets.

A drill is used to remove just the head of the rivet, using a circular motion to help pry the head off.

Blind rivets, pulled rivets, POP rivets—all are names for the same permanent fastener used in many homebuilt and kit aircraft projects. "POP" is a brand name, "blind" refers to the fact that you do not need access to the backside for installation (as a solid rivet requires), and "pulled" refers to the process used by a tool to set the rivet in place. This type of rivet is fast and easy to install, and comes in a variety of sizes and material composition (aluminum and various steel materials).

Although these rivets are permanent, it is very common to need to remove them due to mistakes while building or for required repairs. Removing these permanent fasteners is easy—but extreme care must be exercised if you do not want to damage the hole during the removal process. A not-so-obvious obstacle will challenge your ability to keep the original rivet hole from becoming enlarged while drilling the rivet out. At all costs we want to keep that rivet hole unchanged so that it can be used again with a new rivet and maintain maximum strength.

A spring-loaded punch is used to displace the hiding stem so that the drill bit stays centered.

To remove a blind rivet, a drill bit (the same size as the original hole or a little smaller) is used to remove the rivet's head. While the dimple in the head guides the drill bit perfectly down the center, problems often occur when the tip of the drill meets with the rivet "stem" hiding just below the top of the head. This stem was used by the rivet gun when setting the rivet, and it breaks off just below the head during installation. While designs of rivets vary, many rivets need this stem fragment to remain in the rivet to add extra strength. When drilling to remove, the tip of the drill contacts the top of the stem. What happens invariably is that the drill is pushed off center and the hole becomes distorted. This all happens in a split second and is then too late to remedy.

A spring-loaded punch and a manual pin punch surround a blind rivet.

The solution is to simply remove or displace the stem prior to drilling. Two options are available: a pin punch or a spring-loaded automatic punch. Finding a punch that fits inside the rivet head dimple is the key. Depending on the rivet sizes you are working with, it is important to find one or more punches that can reach into the dimple and contact the top of the stem.

Using some good judgment with a manual pin punch, the right amount of tapping with a hammer (don't damage your airplane!) will move the stem down. The stem does not have to be completely removed—just enough to give the drill bit a little more room.

My favorite stem remover is the spring-loaded punch (from Amazon or Harbor Freight). No tapping is needed; you simply press until the internal spring unloads its stored energy and creates a mild impact at its point. This can be repeated rapidly several times in a row if needed. We just need the stem to move a little bit! The problem with this spring punch is that the tip is too large for the popular 1/8-inch rivets found in many kits. A one-time effort of grinding the tip a little thinner on the bench grinder is all that is needed. It can also then be used for larger rivet sizes. Works like a charm!

The punch is used once again to push the rivet fragment from the hole.

With the stem out of the way, the rivet head can be quickly drilled off using the dimple in the head as a guide. I like to use a slight circular motion with the drill to help pry and break the head off while drilling. Do not drill the rest of the rivet out! Sometimes stainless steel rivets can start to spin while drilling. If this occurs you need to prevent this motion by pinning them down until the head is removed.

Next, using the spring-loaded punch again (or manual punch), the rest of the rivet body can usually be easily pushed out. If you have access to the other side of the rivet, side-cutter pliers can be used to pull the remaining rivet fragment from the hole.

Using this process and always making sure the stem does not disrupt your drilling precision, blind rivets can be removed very quickly and easily, leaving the original hole practically untouched for reuse.


As the founder of HomebuiltHELP.com, Jon Croke has produced instructional videos for Experimental aircraft builders for over 10 years. He has built (and helped others build) over a dozen kit aircraft of all makes and models. Jon is a private pilot and currently owns and flies a Zenith Cruzer.

Download File

Untitled Document Homebuilder's Portal by KITPLANES
Photo by Richard VanderMeulen
John Albritton after his First Flight of his Eze Jet. This day was a long time coming for me. Flying my own jet! This couldn't have been possible without the help and expertise of the Jet Guys. They don't understand the word impossible. If someone tells them it can't be done, they just laugh, and then they do it. This project was not without its …
Rich-Macrafic-RV-7A-N4956TRV-7A N4956T, after a 12-year build, flew for the first time on 10/09/2017 from KRST (Rochester, MN). Everybody talks about the "RV smile" after that first flight.  For me, that came on the second flight.  The first one was approached with trepidation, caused by the combination of a new plane that had never flown and …
After many years of both building and not building (about 50/50) N184GC (One RV-8 for Grandpa Christensen) and I made the maiden flight on April 22, 2015 from Santa Fe Municipal Airport, Santa Fe, NM. That was prior to paint and empty weight was 1,041 lb. Making the first flight in the airplane I built was …

Dynon Avionics' latest-generation SkyView integrated avionics called the SkyView HDX has a newly designed bezel and user controls for easier use while flying in turbulence, plus brighter displays and a reworked touch interface. Larry Anglisano takes a product tour of the HDX with Dynon's Michael Schoefield in this video.
At Sun 'n Fun 2016, Dynon continued to push into the world of non-certified avionics with its SkyView SE, a less expensive version of its popular SkyView EFIS system. Paul Bertorelli prepared this video report.
The G5 is a self-contained electronic flight instrument, which can be interfaced with Garmin's G3X/Touch avionics and autopilot for backup and flight instrument redundancy. The GMA245 and remote GMA245R Bluetooth audio panels have advanced entertainment input functions and onscreen programming.
At Sun 'n Fun 2016, Just Aircraft is showing off its new Titan-powered SuperSTOL XL. Harrison Smith took Paul Bertorelli for a half-day demo flight in the new airplane, and here's his video report.
Kit manufacturer Zenith Aircraft Company has released a new 360-degree VR short video to showcase its kit aircraft and to promote the rewarding hobby of kit aircraft building and flying light-sport aircraft.
Whether you are upgrading the audio system in an older LSA or experimental or building a new project, PS Engineering and Garmin have non-certified audio panels equipped with advanced features better suited for smaller cabins.
Video Archive

IMPORTANT CUSTOMER SERVICE NOTICE TO KITPLANES SUBSCRIBERS:


All mailed correspondence, including subscription invoices, renewals, and gift notices, will bear our address:
PO BOX 8535
Big Sandy, TX 75755

Third parties claiming to be selling KITPLANES subscriptions are not legitimate.