What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

My attempt at a carbon FWD baggage door

It's a good start. The idea is to have 1/4 turn fasteners on the lower corners instead of the key lock and monkey motion.

Noel Simmons
4063664638


IMG_1926_zpsjcvx9mie.jpg
[/URL][/IMG]
 
Vacuum bagging might help with those bubbles and voids.

The general technique isn't hard. This shows the basic plan. The fabric and core are your part, the rest is the process:

ddyvwp.jpg


Here's my vacuum pump and my plumbing:

2eksndz.jpg


The stub vertical pipe below the gauge is a trap.

I take the pvc pipe up to the part and put it under the outer bag. That section of pipe has several holes in it, and I lay some bleeder/breather mat under and over those. Here in Boulder we typically see about 12.5 psi of air and I can recover about 9 psi of vacuum with my simple and cheap set-up, so pvc is fine.

I use heavy but common plastic sheet for my outer bag and duct tape it down. That's adequate. The bleeder/breather mat is common padding from a fabric store, an inch or so thick. ACS sells the release film and the peel ply is polyester aircraft covering (the cheaper non-certified stuff). The pump came from McMaster and is rated for continuous use; I had it run for a week on my boat once to dewater a section of core. It was as good after that as before.

Dave
 
Carbon fiber Galvanic Corrosion & Aluminum

I'm surprised this hasn't already been brought up with this thread. Carbon fiber reinforced composites (CFRC) and aluminum causes galvanic corrosion.

Carbon Composites' Drawbacks

Despite all of the excellent properties of CFRCs, there are issues with using CFRC and metals together. Carbon fibers in CFRPs cause this material to become electrically conductive. The carbon fibers are electrically conductive and electrochemically very noble. Therefore, when a metal is electrically connected to a CFRP, it is more susceptible to galvanic corrosion. This situation becomes worse when a large surface area of carbon composite components is coupled to small metallic parts (such as fasteners, bolts and nuts). In these circumstances, the rate of galvanic corrosion is extremely high due to the high cathode to anode surface area ratio (Ac/Aa). . . Aluminum alloys are extremely vulnerable when they are coupled to a carbon composite.

This was copied from https://www.corrosionpedia.com/2/15...connected-to-carbon-fiber-reinforced-polymers

Hopefully the composite master DanH will pipe in on how to isolate the carbon fiber from the aluminum.
Cheers
George
 
...how to isolate the carbon fiber from the aluminum.

The usual approach is a ply of ordinary fiberglass to isolate the carbon. Alternate approach is two coats of epoxy primer and two coats of paint, then hope it doesn't wear though.

If aluminum rivets are used, they too must be isolated from the carbon somehow. Minimum is to wet-set in a moisture proof sealant. Proseal might do.

Good luck finding a titanium lock assembly.

This is not a great application for carbon.

 
Last edited:
More picture

Did the bonding of the foam reinforcing yesterday. And it turned out really nice. The curve of the door needed to be slightly modified as my quick mold was slightly relaxed. But today the door fits really nice! I need to clean up some edges.


And let me add, there is fiberglass on the surface so the carbon won't corrode the aluminum that has been primed, painted, and clear coated.

And vacuum molding only works if you have a proper mold that will not deflect, inside curves require a very very strong mold!!

This particular door along with airplane will be wrapped

In conclusion: this is the "perfect" and proper size part to make a vacuum mold from. Any takers?



IMG_1929_zpspv0brsef.jpg
[/URL][/IMG]

IMG_1930_zpsk7j2xcn9.jpg
[/URL][/IMG]
 
....And vacuum molding only works if you have a proper mold that will not deflect, inside curves require a very very strong mold!! ....

Actually, they don't, if the part is sealed to the side (typically an extension of the side) that it's up against, and the back side is at ambient air pressure.

Dave
 
Did the bonding of the foam reinforcing yesterday. And it turned out really nice. The curve of the door needed to be slightly modified as my quick mold was slightly relaxed. But today the door fits really nice! I need to clean up some edges.


And let me add, there is fiberglass on the surface so the carbon won't corrode the aluminum that has been primed, painted, and clear coated.

And vacuum molding only works if you have a proper mold that will not deflect, inside curves require a very very strong mold!!

This particular door along with airplane will be wrapped

In conclusion: this is the "perfect" and proper size part to make a vacuum mold from. Any takers?



IMG_1929_zpspv0brsef.jpg
[/URL][/IMG]

IMG_1930_zpsk7j2xcn9.jpg
[/URL][/IMG]


Does the carbon fiber door weigh less or more than the stock Vans baggage door? It looks really cool BTW.
 
I'm going for lighter. And I don't like the modified lock and pins of the stock door so just going with to 1/4 turn fasteners from sky bolt.
 
I'll have to think about that: I know all the best molds I've made by hand and machined have been significantly reinforced. And have had special provisions for the vacumme bag.

However this mold I'm thinking of a two sided hardshell so the inside and lands for the camlocks are perfect and don't need post clean up, beyond the split line. Like the injection molds I machined. The foam core will add the spring as nessisary when the two halves are vacuumed together.

"Quote:
Originally Posted by rvtestpilot View Post
....And vacuum molding only works if you have a proper mold that will not deflect, inside curves require a very very strong mold!! ....
Actually, they don't, if the part is sealed to the side (typically an extension of the side) that it's up against, and the back side is at ambient air pressure.

Dave
 
Dave, one way to think about it is to imagine wanting a half-round cylindrical shell. Get a coffee can and put mold release on it and lay up your part directly on it. Set up the vacuum bag, taping it directly to the can.

There's equal pressure on both sides so the mold doesn't distort.

What did you use for a mold, by the way?

Are you using the stiffness of the carbon panel directly or are you adding a core for a sandwich or ribs?

Also, thanks very much for posting this. I think it's great that you found a good part for converting into carbon.

Dave
 
I want put a baggage door in my RV 14 can you give the page numbers in the drawing section numbers for the baggage instruction so can get a copy from van
 
The usual approach is a ply of ordinary fiberglass to isolate the carbon. Alternate approach is two coats of epoxy primer and two coats of paint, then hope it doesn't wear though.

If aluminum rivets are used, they too must be isolated from the carbon somehow. Minimum is to wet-set in a moisture proof sealant. Proseal might do.

Good luck finding a titanium lock assembly.

This is not a great application for carbon.


This has me concerned for all the places in the RV-10 doors where screw holes are drilled through the carbon-fiber-reinforced portions of the doors for securing door pin blocks, Vans and PlaneAround rack and pinion units, etc. Seems like the cad plating isn't going to fare well in those locations. Do these fasteners need to be inserted wet with neat epoxy or receive some other treatment to prevent galvanic issues down the road, under the paint?
 
This has me concerned for all the places in the RV-10 doors where screw holes are drilled through the carbon-fiber-reinforced portions of the doors for securing door pin blocks, Vans and PlaneAround rack and pinion units, etc. Seems like the cad plating isn't going to fare well in those locations. Do these fasteners need to be inserted wet with neat epoxy or receive some other treatment to prevent galvanic issues down the road, under the paint?

Don't get real wadded about it. Apparently folks are not having problems with that application.

I'd put mine in wet, but that's just me.

Pretty sure Niu is a respected reference.
 
Help

I am having a terrible time with the baggage door. What you did seems the perfect solution. I would like to talk to you about the process. John @sharpestuff.com 810 516 9332

Did the bonding of the foam reinforcing yesterday. And it turned out really nice. The curve of the door needed to be slightly modified as my quick mold was slightly relaxed. But today the door fits really nice! I need to clean up some edges.


And let me add, there is fiberglass on the surface so the carbon won't corrode the aluminum that has been primed, painted, and clear coated.

And vacuum molding only works if you have a proper mold that will not deflect, inside curves require a very very strong mold!!

This particular door along with airplane will be wrapped

In conclusion: this is the "perfect" and proper size part to make a vacuum mold from. Any takers?




IMG_1929_zpspv0brsef.jpg
[/URL][/IMG]

IMG_1930_zpsk7j2xcn9.jpg
[/URL][/IMG]
 
Corrosion?

For you composite experts. Standard use of carbon cloth on our planes it to have it impregnated with epoxy resin. Assuming that there is no raw carbon to aluminum contact because of the resin, does this eliminate the corrosion problem?

Carl
 
For you composite experts. Standard use of carbon cloth on our planes it to have it impregnated with epoxy resin. Assuming that there is no raw carbon to aluminum contact because of the resin, does this eliminate the corrosion problem?

Carl

Mostly, but not entirely. Epoxy is pretty much liquid-water proof, but not gas-impermeable. So over time in humid environments, enough water vapor can diffuse into the carbon-epoxy laminate to provide the electrolyte needed to start corrosion at the bond interface with aluminum. A layer of glass, as DanH described, is a pretty standard insulation step. Other approaches are to bond a pad of Garolite G-10 to the surface where plate nuts are bonded on to spread load out from fasteners into the composite structure, or a thick layer of "liquid shim" Hysol 9430. We usually assemble fasteners 'wet'.
 
Baggage Door Kit Idea

I am sure there is a sizable market for a good forward baggage door kit that has a flush lockable latch like on the production airplane. Fitting the metal baggage door with the wonky cabinet key latch is a PIA. From stock, the door is light weight and strong but it is so time consuming to build. Plus having to line up the plastic lock blocks is 2 x PIA.

So if there is an entrepreneur mind that can create a kit to speed up this build, there is a market for it. This is the part that RV8 builders I talked to complain about.
 
Question: Is the fuselage contour in the vicinity of the baggage door the same on the -1 matched-hole fuselage kits as the earlier kits?

This might be a product that HP Aircraft LLC would be interested in developing, but not if there are two different fuselage shapes.

We would also welcome suggestions for alternative latch/lock arrangements.
 
Question: Is the fuselage contour in the vicinity of the baggage door the same on the -1 matched-hole fuselage kits as the earlier kits?

This might be a product that HP Aircraft LLC would be interested in developing, but not if there are two different fuselage shapes.

We would also welcome suggestions for alternative latch/lock arrangements.

They’re not the same. There are two different upper fuselage shapes in that area of the RV-8 between the two versions of the kit, and specifically the difference is in the contour/shape of the top forward skin and bulkheads. The earlier RV-8 and prepunched RV-8 upper forward fuselage bulkheads and skins are not the same. The firewall actually is compatible, but not the upper bulkhead half that’s located in the baggage compartment, and there are some other subtle but important differences in shape and fit of parts. The baggage door shape is definitely not the same between the versions.

That said it *is* possible to retrofit a specific set of parts from the “new” fuselage kit to the “old” version in this area, and thereby use the “new” baggage door (and several other associated parts) on the original version. The new baggage door is definitely easier to fit than the original version. That’s why I made the swap of the parts on my project. But, you have to use the a specific list of parts in total - you cans just scab parts together randomly. They won’t match up if you do. And for those who are not aware, the original fuselage kits were shipped up u til about 2005-2006 (I’d have to go to scanned records to find out for sure the dates) and since then it’s been the prepunched, updated fuselage kit.
 
Last edited:
Thanks Greg, that is very helpful.

I wonder if there are any builders still working on the earlier kits that might still want a baggage door? Or would the market be pretty much only be for the new matched-hole kits?

Then the remaining thing is that we would need someone to volunteer their matched-hole RV-8 fuselage for us to make a mold from. Or wait until I am a repeat offender -- which is being contemplated now.
 
That said it *is* possible to retrofit a specific set of parts from the “new” fuselage kit to the “old” version in this area, and thereby use the “new” baggage door (and several other associated parts) on the original version. The new baggage door is definitely easier to fit than the original version. That’s why I made the swap of the parts on my project. But, you have to use the a specific list of parts in total - you cans just scab parts together randomly. They won’t match up if you do. And for those who are not aware, the original fuselage kits were shipped up u til about 2005-2006 (I’d have to go to scanned records to find out for sure the dates) and since then it’s been the prepunched, updated fuselage kit.

Greg,

I have been working on a 2001 vintage QB kit I picked up recently. I have been contemplating ordering the new baggage door parts for this kit considering all comments I've seen about how much a pain the old door is to assemble. Is it possible to use the new door parts on this old kit? The original builders number is 81426, and it's QB #934. If so, is there a list of parts necessary to use the new baggage door?

Thanks!
 
Pre-punched, not necessarily matched hole. FYI. Plenty of matched drilling still happens throughout an RV-8 fuse project. :)

I made the distinction because even the early (pre-2006) fuselage kits are (mostly) pre-punched. I suppose we should just refer to the newer kits as the -1 fuselage, but some may not know what that means either.
 
Greg,

I have been working on a 2001 vintage QB kit I picked up recently. I have been contemplating ordering the new baggage door parts for this kit considering all comments I've seen about how much a pain the old door is to assemble. Is it possible to use the new door parts on this old kit? The original builders number is 81426, and it's QB #934. If so, is there a list of parts necessary to use the new baggage door?

Thanks!

That's pretty much exactly the vintage of my QB kit.

If you have not yet installed the top-forward skin (the one the door is cut out of) it might be realistic to tackle this. I will have to look up the accurate list of parts that have to be changed out but I know the list of PP parts you'd need would include at least these and possibly more (I am working from memory and don't have the parts list or RV-8 plans in front of me right now):

  • Top forward skin
  • All baggage door components
  • Upper bulkhead section that separates avionics bay from the baggage compartment
  • The spacer strips that fit between the bulkhead/firewall and the top forward skin (on which the baggage door rests when closed)
With the correct parts it works and is a close fit in my experience. It might take a small amount of massaging and "convincing" when it comes to lining up with the longeron rivet line. The fit of all these parts is fairly precise.

And that also assumes the parts are available, of course! ;)

Bit of a can of worms, but hopefully that's at least a little helpful. :)

EDIT: I found the details of what I did on my project, see post 29 below.
 
Last edited:
I made the distinction because even the early (pre-2006) fuselage kits are (mostly) pre-punched. I suppose we should just refer to the newer kits as the -1 fuselage, but some may not know what that means either.

Internally it's referred to I think as the "PP fuselage." Heck I can't remember and I haven't had time to look at my project (let alone work on it!) for a year or more. Rian did all that fuselage update work when he was an intern. Now he runs the dang place!

I'll gather some more info on the differences when I come up for air. Would make an interesting trivia video or article maybe.
 
Okay, I found my notes from a couple of years ago, so here you go. NOTE: Your mileage may vary, don't blame me when it gets a little/lot goofy, etc. etc.

This is for people with the older/original RV-8/8A fuselage kit who want to use the more modern baggage door design since it's "more buildable" (read: easier to get it to fit well) than the original door. You'll have to replace more than just the door parts to make this work. There's no way to get the -1 door to fit in the original fuselage correctly without changing bulkhead/skin/other parts since the bulkhead and skin profiles are different.

Refer to DWG 84 from the RV-8 plans.

Notes:
  1. Owners of the older kits don't have that DWG 84, but when you create an account on our web store and then register your airplane/kit there, you'll automagically get access to the latest kit plans for the RV model(s) you own. This is a good example of why we decided to do that on the web store.
  2. Be sure to use the latest parts - the ones with the largest trailing number after the dash on each part (so, -2 or -1 etc. depending on the specific part). FYI, the trailing "dash" number is the revision number for that part, and this same scheme for revision numbering is used across each of the RV models. #themoreyouknow

F-866B-1 Fwd Baggage Bulkhead
F-821-1 Fwd Top skin
F-821B-1 Aft Baggage Door Support Strip
F-821C-1 Fwd Baggage Door Support Strip

F-873A-1 Baggage Door Skin
F-873B-1 Baggage Door Fwd Rib
F-873C-1 Baggage Door Aft Rib
F-873D-1 Baggage Door Inner Skin
F-873E-1 Baggage Door Outboard Rib
F-873F-1 Baggage Door Angle
F-873G-1 Hinge Support
F-873H Spacer
And all other F-873 parts as well


Pretty sure you will also need this - my memory is a bit vague on this one: F-803C-1 Instrument Panel Attach Flange.

If you're using the original fuselage kit's instrument panel you should be prepared to do some shimming and other smallish adjustments to get things to fit (you'll have some gaps on the lower sides, etc.). Or, replace the instrument panel with the new one to get a closer fit if you haven't built the panel yet.

And I can't guarantee all of these parts are readily available, at least not right now. YMMV.

Okay. Have fun. And please just don't blame me when you get frustrated. Worth it in the end, probably maybe. :)
 
Last edited:
Thanks for the info Greg! I'm a little ways off from this task, so everything is easy to change now, relatively speaking that is.
 
I just finished fitting my baggage door about 6 months ago. I had the newer kit so the baggage door structure wasn't too difficult. The trick was to get the latch blocks and the structure to fit precisely and don't bind as you turn the key to lock the door, and everything to line up square and flush. This is the part of your airplane all RV8 builders will scrutinize when they look at it. No pressure eh. What I learned was it took me all the various different building skills from the 2 1/2 years of building to ensure everything fitted correctly. I had to redo a few parts, a few re-orders from Vans, at least one customized part to finish it off. My one advice is don't rush it, you can do this part toward the end. Your building skills will be much improved before tackling the baggage door.
 
Last edited:
If you have not yet installed the top-forward skin (the one the door is cut out of) it might be realistic to tackle this.

I've told this story on myself before.

Look close at 5551, and compared to others you'll see a bit more space between door edge and opening edge, all around the door perimeter. The door closes against a flange, so it's not obvious.

That's because I carefully cut that section from the door opening in the top skin...then built the door with it, not realizing there was a real door skin in the bottom of the shipping box.

I don't know, but it may be easier to get a great fit by working with an unpunched door skin. For sure, it proves even an idiot like me can build a decent door. Don't let a mouse become a monster in your head.
 
Back
Top