Rivets, Fasteners and Torque - Part 2

This article collects Builder Technical Support answers on rivets, fasteners and torque.

Improperly set rivets on a previously completed SB

If you are inspecting an aircraft where the doubler kit was installed but rivets are clenched, smiley'd, over- or under-driven, the standard guidance is to drill those rivets out and replace them. CherryMAX pulled rivets are an acceptable substitute for AN solid rivets in cases where back-riveting is no longer possible — confirm the specific CherryMAX part number with Builder Tech Support for your situation. Note that CherryMAX rivets require a different installation tool than standard blind rivets; verify you have the correct puller mandrel before proceeding. Avoid Hi-Lok substitution unless explicitly authorized.

Where builders buy

Well-known builder-tool suppliers include Cleaveland Aircraft Tool, Avery Tools, and Brown Tool, among others. Each offers RV-specific tool kits packaged by kit section (empennage kit, wing kit, etc.). Buying the package is usually cheaper than piecing it together. Harbor Freight is fine for clecos, drill bits, and cheap consumables but not for primary tooling like squeezers and rivet guns.

RV-12 / RV-12iS specific

The RV-12 uses primarily blind (pulled) rivets, so a quality blind-rivet puller matters more than a rivet gun. A hand puller works; a pneumatic puller is a quality-of-life upgrade for the wing.

Common gotchas

• Buying a $300 set of dimple dies you'll only use four sizes from
• Skipping the edge deburring tool - poor edge prep is the most common cosmetic problem on first kits
• Cheap drill bits - cobalt #40 and #30 in good condition are non-negotiable
• No air compressor sized for a squeezer (4 CFM minimum, 6+ CFM preferred)

RV-14 push rod washers (NAS1149F0432P with MS20392-1C11)

On plans page 09-24, the called-out NAS1149F0432P washer can have a larger ID than the head of the MS20392-1C11 pin, allowing the head to slip through. If you encounter this, contact Builder Tech Support with photos — they will spec the correct replacement washer.

Substituting blind rivets for solid rivets

On RV-14 Section 29-16 and similar locations, builders sometimes ask whether AN426AD3-4 solid rivets can be replaced with blind rivets in tight spots. Acceptable substitutions and required hole sizes vary by location. Common substitutions include:

• MK-319-4-3 - requires hole enlarged to #35
• CR3243-4-3 - requires hole enlarged to #27

Do not substitute without confirming the specific location is approved. Contact Builder Tech Support with the page reference, location, and proposed rivet.

Mis-dimpled holes (page 26-19, F-01458A-L)

If you mis-dimple a corner #40 hole, options include reordering the part, fabricating a doubler patch, or sandwiching the damaged area between two new pieces. Contact Builder Support with photos before fabricating any repair.

Wing walk doubler countersink

The wing walk doubler is countersunk on the top surface. Builders ask whether the dimple goes in the doubler or the skin - the doubler is countersunk (thick part) and the skin is dimpled (thin part), then they mate flush.

RV-10 page 28-3 countersink reference to "page 13-3"

This is a known cross-reference error in some plan revisions. The intent is a standard machine countersink for the #8 screw — there is no special procedure beyond a standard 100° countersink to the screw head. Confirm with the current revision of the plans before final-cutting.

WD-1002 bracket gap (RV-10, page 29-14)

A 1/16 in. gap between the left and right WD-1002 brackets and the mating structure usually indicates the rivet holes in the bracket are off by that amount. Don't try to pull the bracket flat with clecos and force-rivet - send photos with your builder number to Builder Tech Support. The typical resolution is a replacement bracket.

RV-12 tail kit hinge rivets (SB-related)

If the outboard hinge bracket assembly calls for 3-5 rivets to attach the F-12191 pieces and the kit doesn't include the right rivet length, supplement from existing stock and notify Van's. Van's tracks these reports to update kit packing lists - report your kit serial and the missing rivet size to Builder Tech Support.

What if I damage a skin hole during rivet removal?

If you over-drill a hole, stop and contact Builder Tech Support with photos. An oversized hole may be addressed with a slightly larger rivet, but the call belongs to Van's engineering.

Overview

If you're working through the RV-12iS plans, several recurring questions come up around rivet length, dimpling, and parts that arrived already finished.

System block stud torque (page 21iS/U-21)

After installing the six system block studs and nuts in F-01276-1, tighten the nuts to the specified torque rather than running them all the way down by hand. Refer to the standard hardware torque table at the front of the plans for the stud size called out. If a torque wrench is not available, contact Builder Tech Support before proceeding — do not estimate torque by feel on structural fasteners.

LP4-3 in place of Cherrymax

LP4-3 blind rivets are not equivalent to Cherrymax CR3213 in structural applications. If material is too thin to fit a Cherrymax (e.g., RV-9A E-902 to E-904), do not substitute LP4-3 without explicit Builder Tech Support approval - the load path may not support it.

Floor Board Rivets and Legacy Parts

Many legacy RV-4 hardware items (floor board rivets, specific kit parts) may not be carried in current Van's Parts inventory. Contact Builder Tech Support to check current parts availability, as inventory and sourcing capabilities may have changed.

RV-15 rivet sizes

The RV-15 program status and available rivet specifications may have changed since this article was written. Check the Van's Aircraft website or contact Builder Tech Support for the current status of the RV-15 kit.

Source tickets: 141227, 140885, 140880, 140246, 121441, 121370, 121366, 121346, 121316, 121238, 121206, 93336