C

Captain Avgas

Well Known Member
I'm currently working on my canopy (RV7A slider). It appears to me that there are a couple of obvious places where rain in flight would enter the cockpit.

One is between the plexi and the overlapping rear skirt (where it would run backwards and drip into the baggage area). The other is between the plexi and the side skirt.

What have others done to prevent water ingress in these locations.
 
Extend the doghouse 1 inch

We modeled the doghouse on our 9A slider using a friend's design. His doghouse extends past the rear skirts and does not use the little piece of delrin that slides to fore and aft. Instead, he has a piece of insulation.

On the underside of aft edge of the rear skirts, he placed very thin insulation which rests on the fuse. His skirts (and ours) align to the edge of the fuse extremely well. Many hours went into that aspect till we achieved the final fit.
 
Rain seal

I have seen several sliders that have a small bead of proseal installed where the plexiglass/fiberglass/metal mate to the canopy and windscreen. The bead is only wide enough to seal the gap (probably 1/8" or 4/32" for Van :) ).

Keith
 
Additional comment on the seal

The local painter that routinely uses proseal for this application applies the proseal after the plane is fully painted.

Keith
 
Proseal after paint?

KiloWhiskey1 said:
The local painter that routinely uses proseal for this application applies the proseal after the plane is fully painted.

Keith
Click to expand...
If he applies proseal after paint to prevent leaks, what does he do with the ugly gray line of proseal across the front of the airplane?

Surely there's something CLEAR that will accomplish the same task. Or, perhaps the bead he uses is very small.

I'm coming up on this section real soon so any thoughts are appreciated.
 
MrNomad said:
We modeled the doghouse on our 9A slider using a friend's design. His doghouse extends past the rear skirts and does not use the little piece of delrin that slides to fore and aft. Instead, he has a piece of insulation.

On the underside of aft edge of the rear skirts, he placed very thin insulation which rests on the fuse. His skirts (and ours) align to the edge of the fuse extremely well. Many hours went into that aspect till we achieved the final fit.
Click to expand...

Thanks for the comments Mr Nomad, but I'm not referring to the intersection of the rear skirt and the fuselage. I'm referring to the intersection of the plexi and the rear skirt. The rear skirt is not shingle laid under the plexi to prevent water entry...it's on top of the plexi. Therefore water being driven backwards at high speed must find its way back under the aluminium. Then it can run backwards over the plexi and drip over the edge into the baggage area.

There's a couple of possibilities. One, apply a thin bead of sealant when rivetting the skirt to the plexi......downside is that the bead will be seen through the plexi from inside the cockpit and might look very ugly.

The second option might be to apply some sealant either before or after painting...downside is that it will probably not stay adhered due to differential thermal expansion.

A third option may be to run a bead between the plexi and skirt at the rear of the plexi (rear edge)...downside is that water may be trapped under the skirt and cause corrosion over time.

I'm beginning to suspect there might be a whole lot of very leaky RVs out there.
 
Proseal or maybe sekaflex

The proseal actually looks great. If done right you can get a very small uniform bead that transitions nicely between the plexi and the aluminum or fiberglass.

Another option is to use Sekaflex to bond the plexiglass to the skirt. Three RVs that I know of from Don's Dream Machines in Griffin, GA are now flying with this method. They used Sekaflex to mate the windscreen to the fuselage and the canopy to the skirts (no screws or rivets at all). If done well, the finished product looks like an auto windshield install. If you use this method, leaking will not be an issue where the Sikaflex is applied. If you search this site for Sekaflex, I would bet you would find some info and possibly pictures.

Keith
 
Welcome to VAF - The greatest collection of RV owners, builders and enthusiasts in the world!

I am building a 7 and have researched with no smoking gun for this. Abby at Flightline Interiors makes a ripstop cover for the gap between the panel and sub panel to shed water.

Some have 6's and say it has never leaked. You will have to identify the gaps, and locations for intrusion and seal them. Vans makes a "D" seal for the 7, not sure about the 6. Suggest you order the plans CD if you don't have them to understand how it is made and seek possible solutions.

Searching VAF is a start, there are extensive archives. I use the google method,

just enter site:vansairforce.com tipup leaks - - it will search the site for you.

Again, Welcome!
 
KiloWhiskey1 said:
The proseal actually looks great. If done right you can get a very small uniform bead that transitions nicely between the plexi and the aluminum or fiberglass.
Keith
Click to expand...

I think every one of our local group of builders here did this...just mask the canopy and the skirt extremely closely, and then lay a very small amount of proseal down and create a fillet with a popsicle stick or even your finger. Before it hardens, carefully pull off the mask. It makes a very neat, even, waterproof seal between canopy and skirt. We've done it on -8s and -7s (tip-ups and the rear window on them). 400 hours here, no loss of adhesion. My buddy's 8 has 1000+ hours, no issues. All were done before paint, and the painter just masked so that the proseal itself got painted. End result is very nice.
 
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