Originally Posted by Strasnuts
There should be no less than 1/4 " reveal between the inner door skin and the outside edge of the fuselage flange (with the seal off) for the common McMaster 3/8 bulb seal to squish into. If it is less than 1/4 you will have a lot more force.
A thing to watch is when the angled pins begin to seat they can bind against the cam shoulder resting on the fuselage block. I had this when building mine. I relieved the cam block by cutting a half circle where the cam shoulder sits (3/4" diameter). You can also lower the cam block. The way to test this is to remove the cam block and see if there is the same force on the pins while closing.
Other parts that can cause friction is the pushrods. Make sure the exit blocks are parallel and the hole drilled in the fuse is parallel to the pushrod travel. I counterbore all the PlaneAround blocks almost all the way through until the last 1/4". I keep that at 7/16 so the pushrods don't have to be perfectly lined up. I chamfer the big hole to the smaller exit so that they wouldn't catch.
Hope this helps
I'm at a frustrating point in my build. 13 months ago I spent a week molding a lip in place on the doors using the McMaster 1120A413 seal material as a female mold. Now a year later I'm sanding and filling doors for a final perfect fit flush to the cabin top and realize, Hey! - I should trial fit the seals before finalizing this little detail...
Somehow I seem to have slept through the threads (that I even posted in) about the proper set-up for using these seals instead of Van's: I have less than 1/8' clearance in some areas. Needless to say, my beautifully contoured doors won't come close to closing with the seals on. I've been grinding away at flox and pink prepreg for the last 3 days.
I think what Strasnuts meant to say is if you only have 1/4" of gap, you will need three linebackers pushing on the door to get it to close. I now have one door with .30" clearance all the way around and it still won't close with those 3/8" bulb seals on. Portions of the doorway are now so thin the seal won't stay on - almost knife edge. Time to add some flox on the inner doorway edge to build it back up. This will likely necessitate some spot repairs to the interior paint job.
I have decided not to sand the doorway any further into oblivion until I try the next (and only) smaller size seal McMaster seems to offer - a 9/32" diameter bulb on a 3/16" width C-channel. I'm hoping this will grip the sharp edge of the doorway better in more places, and that the 3/32" added clearance will let the door pins engage.
At this point I'm thankful that this screw-up, like virtually any with fiberglass, is fixable with sufficient time (or $$time$$ as Bob Nuckolls likes to say), effort and resin. The "elephant" just got a few dozen bites larger, but it's being eaten nonetheless.
Hop-Along Aerodrome (12VA)
RV-6A - N30YD - flying since '98
RV-10 - N130YD reserved - under construction
donating monthly to the VAF - thanks, Doug