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Cowl to Firewall Piano Hinge Questions

rvanstory

Well Known Member
I am ready to install piano hinge on firewall for the cowl attachment later. I've been advised to NOT use Van's supplied piano hinge for lower cowl attach to firewall due to premature failure of eyelets. I do not want to use Skybolts, so my options are extruded hinge or screws. Considering using extruded hinges on all of firewall just for longevity. Here are my questions:

1. Are the hinges supplied by Van's aluminum or Stainless Steel? I can't tell from their website. ACS only list .062" hinges in stainless, and the Van's hinges are .062" thick, so created some confusion for me.

2. Planning on ordering the 1.75" x .051 extruded hinge from ACS and using this instead of the 1.5" x .062 hinge supplied by Van's. Will thinner material, or wider width cause any problems for me when attaching cowl?

3. Some have said you can use a hinge on lower cowl IF you use extruded. Has anyone that has installed extruded hinge on lower cowl attach point been disappointed with the results? Would you advise screws or extruded hinge if doing over?​
 
Hmm, looks like Vans does sell the SS (CRES) hinge in the “SSP” series piano hinge. Though I couldn’t find an extruded (MS20001) hinge on their site.

Take a magnet to it, 300 series CRES should still be slightly magnetic at the bends. Take out the pin first, obviously.

Edit: ferrous, not magnetic.
 
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I did screws on the 6, but am trying hinges on the 10. I wouldn't trust the std hinges for the bottom (very rough environment down there). I bought a couple feet of SS hinge from Mcmaster Carr. Same dimensions as the std hinges.

Larry
 
I used screws on the bottom of the -6 and they have been foolproof. I'm doing the same on the -10.

On of the nice things about the screws is that you keep your hands clean and cool when installing/removing them. With hinge pins, you're reaching into what can be a hot/dirty area to mess with them.
 
I used a flat piece of stock and 6-#6 screws and appropriate nutplates. 900 hours and still looking like new.
 
Hinge in the bottom of my RV6 (2000), camlocks on the bottom of my first RV8 (2008, in fact Skybolt camlocks everywhere), screws/nutplates on the bottom of my current RV8 (2018). Bottom line for me: I lost a couple eyelets on the RV-6, both RV8?s were and still are fine, but the screws/nutplates are much less expensive and way easier to install than the camlocks. The camlocks took less than 30 seconds to remove or install (on the bottom), and the screws take about a minute to remove/install. I?ll take the screws every time on the bottom. Hinges elsewhere - my opinion..
 
I did it the same as Bill. Some flat stock aluminum on each side. Rivet it to the lower flange of the firewall. 6 screws on each side of bottom cowl, and I used tinnerman washers. Nice and solid.
 
Skybolts?

Why not 1/4 turn fasteners?

My perspective is based solely on the future removal and installation of the cowl and didn't really consider costs (mostly because it's fairly trivial in the budget of building a 10, or just about any airplane for that matter)

On my most recent build, I used 1/4 fasteners on the upper cowl (not from Skybolt, but just plain ol' camlocs that I bought off of eBay of all places), and then screws for the lower cowl. The upper cowl comes off in just a couple minutes and is a breeze to line up and install, so I'm very pleased with the fasteners and ease of use and plan to do the same thing on my current build.

Screws do take longer to R&R, but I like the security of screws with nutplates for the lower cowl and prefer them there.
 
Just replace the bottom hinges with the extruded kind - solves the problem. Stock hinges everywhere else - with the option to replace the side hinges with a wider hinge. This way you can offset the hinge seam so the eyes are not at the cowl seam.

Carl
 
Dang it, Carl!

... I forgot to do that offset trick.

Did so on the wingtip hinges to hide the eyelets from the gap, then turned around and mounted the FW/cowling hinges per plans. :mad:
 
Using screws

Does anyone have build pictures of the lower cowl installation using screws?
Allen
7A very slow build
 
ACS specs say the ms20001p4 is .040 thick and the ms20001p5 is .051. I found another website that specs them both at .056. Is the ACS ms20001p4 really only .040 and if so is this thick enough for the bottom hinge. I am at the same place as the OP and am trying to decide which hinge to use.
 
... I forgot to do that offset trick.

Did so on the wingtip hinges to hide the eyelets from the gap, then turned around and mounted the FW/cowling hinges per plans. :mad:

Sorry, but that's funny. I suffer from the same level of OCD. You're probably going to redo your cowling hinges now, aren't you. ;)
 
It's very tempting, Mike!

The grey goo (FireBarrier) that's cured all along the edges of my stainless steel and Fibrefrax will make removal and replacement something of an issue.
 
It's very tempting, Mike!

The grey goo (FireBarrier) that's cured all along the edges of my stainless steel and Fibrefrax will make removal and replacement something of an issue.

Is it possible to "relocate" the seam, by grinding back the aluminum a bit and adding fiberglass to your cowling?
 
Maybe.

At first glance that sounds easier.

Since I haven't yet fitted the cowl, and there's trimming to be done on the aft edge, I suspect there'd be no need to add any fiberglass, just trim less off. Probably 1/16" is all that would be needed to hide the eyelets.

One would have to mind edge distances on the rivets, and the neatness of the cut line. How good are you with a Dremel? Do ya feel lucky? :D
 
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