Panther 92

[danweseman]

A couple of quick points
1. Do NOT think that with a "Lycoming" you will have a HEAVY engine up front . The Panther was designed around the Lycoming O-320 ! It has the best all around CG !! I have tried many times to break the notion that because we used a Corvair on the prototype it was "designed" around it. You do not need or want extra weight in the tail of any Panther, unless you are like me and want 0 baggage capacity and the very lightest nose aircraft possible for better spins and snaps!! With the lycoming We recommend the battery on the firewall!
2. You will add more weight than a few OZ if you paint the mating surfaces with epoxy. I strongly suggest you do not bond your spar caps together before riveting. The fuel tanks and forward fuselage skins are bonded with polysulfied fuel tank and bulkhead sealer. If I were to contemplate bonding things like the skins to the ribs i would use it. This is what its made for ! We bond the forward fuse skins in place with it.

How about another silly idea? Speaking of weight and simplicity, would it be completely impractical to skip setting up the traditional heating system and substitude it with, for example, an electrically heated motorcycle vest and a small 12v heater/blower for windshield defrosting? I had no heat in my Onex and wore a plug-in 12v motorcycle vest on a couple of occassions when it was cold -- that thing keeps you cozy and comfy you wouldnt believe it! I wear it on those rare occassions when i feel like taking a bike ride when it's in the 30-50s -- it keeps me warm even though i am out in the open going at least at the spead limit. But the heated vest wont help with conopy frosting, hence the thought of installing a small electric heater/blower.
All this would be much simpler and lighter than the traditional exhaust muff setup.

Totally agree it's not necessary (i recognized it at the outset). Just as it's not necessary to build experimental airplanes or fly for pleasure. And I did acknowledge that it will add weight (less than an oz), which may not be a bad thing for my setup with a heavy engine in the front.
My point was that I dont think it would do any harm, wouldnt it? And I want to do it for the heck of it -- the same reason we are all building airplanes.
BTW, West wholeheartedly supports using their epoxy for aluminum bonding -- it's on their website with detailed instructiins on how to prep it (they basically say just sand it and degrease it prior to bonding). As far as I am concerned, West is no less reputable than the Loctite brand and I have no reason to doubt their recommendations. Not that it matters in my case since I am not trying to substitute the designed structural bonding by riveting. I just want to mess around a little with some epoxy. Give the man a break and let him play a little in his sandbox, but please speak up if he starts eating sand, so to speak...

Ykachuro, Loctite makes a product that is made to bond aluminum to aluminum also wood and steel. It is called Loctite
9460 Hysol. I used it on my Panther build in a few places more for peace of mind then anything else. One place I feel it is needed is on the cowling reinforcing angles that rivet to the jogall strip and firewall for the lower cowling. Were you are talking about using a epoxy I don't feel is necessary as it will only add complexity and weight with no benefit. That my two cents worth,enjoy your build

Waiting for some tools and some parts to finish the tail. Then it will be some weeks to get the rest of the kit.

Decided not to save money on the engine and instead save money on the stuff that adds weight, such as lights and avionics. So, looking now where to best source a new IO340 and will go with whatever lightweight options are available.

Looked into thhe aluminum/epoxy issue. There apears no conclusive agreement. The concensus is that preparation is what makes it either stick or fail. There are curtainly structural aluminum laminates in auto, boat and airplane commercial production. But the industrial methods are too much for a homebuilder. There are some reported successes in structural application where the aluminium is prepared by "wet" sanding with epoxy resin -- whereas the metal is not allowed to oxidize. It seems that the aluminum oxide layer is the culprit of failures.
Again, i am not thinking about substituting riveting with epoxy bonding. I am just thunking about "painting" epoxy resin on the surfaces to be rivetted immediately prior to riveting. I may just do scotchbrite in epoxy just before riveting and may even wipe off whatever excess epoxy residure remains after that prior to riveting. In a couple of places, as an experiment and nothing else. I dont see how that would compromise the design safety by any means. Or I may just bond together a couple scraps of aluminum and see how it holds together....

I would not suggest using epoxy to laminate the spar channels and stiffeners. It's just not necessary and West is not the product to use for bonding aluminum together.

If you want some extra piece of mind to eliminate the "possibility" of future smoking rivets in the spar structure then I would suggest using AN426AD-4 and AN470AD-4 solid rivets and using a pneumatic "C" squeezer to set the rivets. You can always sell the C squeezer to an RV builder on the VansAirForce.net site and get a good portion of your money back, or add it to your tool collection. Every now and then you can find a reconditioned squeezer cheaper on ebay and the like.

http://www.yardstore.com/squeezes/pneum ... -yoke.html

Sorry to hear about your place in St. Thomas, and another storm is on the way. My best goes out to everyone affected by these hurricanes. Yes, building the Panther helps with good spirits

Ordering the rest of the kit and opting for pre-built wing spars, fuel tanks and glued canopy. Would be cool to finish in time for Oshkosh '18... dream on

Looks like I have time to work on the Panther. St John, having been hit by Irma directly (winds of well over 200mph), is simply destroyed. Our house has survived, but severaly damaged. There is no way to get there for now. No power, nothing, no building materials. People who stayed, are simply trying to survive. So, we are in Colorado for the time being. And I find Panther building keeps me in good spirits.

As I am working on the tail spars, i am thinking about painting on a thin layer of epoxy (West System) between the spar channels and the stiffeners immediately prior to the rivetting so that the pieces are "glued" together in addition to being rivetted. Granted, it's not necessary by any means. Can't think how it could do any harm either. Why do it? Well, i feel like it will give me a bit of extra peace of mind. Once skinned, the spars cant be visually inspected. The spars are subject to cyclic loads. I've seen my share of smoking rivets I would just feel better that there is an even lesser chance of the spar channel and the stiffener coming undone if they are held by "belts ans suspenders". I am really talking about a thin layer of unthicken epoxy resin -- thickness similar to what you'd have if you had those pieces primed. The added weight would be maybe an ounce altogether -- probably as much weight as I took off while rounding the aft stiffener to fit the channal. Considering that I plan to do a OI320/340, i could use an extea once of weiht in the tail.

Okay, it's time for a humble confession.

First, yes, it's not a big deal to drill out one or two stainless rivets. But... it is impractical/impossible to drill out 40++ of those, especially with no access to the back of the rivet to keep it from spinning. So, if you think about stainless rivets, think twice and think hard!

As to myself, I am ordering a new left elevator (the skin, the ribs, the trim tab support). Last night I was excited to finish my second elevator in just two days since I started the build and rivetted it tigether while forgetting about the main hinge. Of course I used CCP rivets all around and it was a beautiful job! Except for ine detail....

Speaking of drilling out stainless rivets, there is a good video on the EAA website called "REMOVAL OF STAINLESS STEEL PULLED RIVET" Here is a link, but if the link goes bad, just search the title:
http://www.eaavideo.org/detail/videos/f ... =1&q=Rivet
I will be practicing it tomorrow . Will try to remember to document it in my photo log.