Rebuilding 1938 BC-65

[Guest]

Re: Rebuilding 1938 BC-65

ahh I see

My wings initially had some issues there too.

I believe that my problems were caused by the fabric being attached to the aileron bracket and trapping water/moisture.

So upon recover I cut all fabric away from the bracket so nothing gets trapped.

It appears to be ok now but since we have had this discussion I will double check.

Thanks, Dave.

[HPsauce]

Re: Rebuilding 1938 BC-65

All this talk of wings gets me thinking of another topic I'd like to discuss. Perhaps someone can point me to another thread here but so far I haven't found too much. I'm interested in the design of the airfoil and is wondering if anyone out there has ever experimented with it. Like adding flaps or VG's for instance. I found a website which claims to build T-cart wings with flaps?

http://www.de-aircraft.com/wing.html

Anyone heard of these fellas?

Are flaps even necessary? Taylorcraft didn't seem to believe so.

[cvavon]

Re: Rebuilding 1938 BC-65

I have VG's on my plane and they were one of the best and cheapest things i have done to it dropped the stall speed about 5mph or stalls at 35 mph +/-, this helped the short field landings a lot, D&E are a good company and sell good parts.

[Robert Lees]

Re: Rebuilding 1938 BC-65

No; flaps are not necessary. In the flare, the whole wing is a flap.

I had a few hours in the F22, and all the flaps did was to reduce the stall speed by 2mph. Mind you, the flap lever (like the Piper Pa-28 lever) was a useful place to rest one's elbow.

[HPsauce]

Re: Rebuilding 1938 BC-65

Gentlemen,

Life has sure taken me far from this project. Over the last 3 years I've lived way south on the Idaho/Canada border (Cranbrook, BC), Whitehorse Yukon Territory and finally am back home. Worked server all flying jobs and now I finally got on with an airline in Prince George BC. So the Taylorcraft I am finally close enough to to begin. I have decided to go homebuilt. I had an AME take a lot at it and he says everything appears to be in good shape. I would still like to have a person well experienced with wood spars take a look at them but that is still always down the road. I've pretty well gut the plane and tagged and bagged everything. Only thing remaining on the fuselage would be the fabric, firewall, engine mount, and the wood supports that run along the roof and along the length of the fuselage. The actually term for these has escaped me. I know that some taylorcrafts had metal and some had wood. I'm assuming that the older planes used the wood. Oh! And control cables are still in the fuselage but just hanging there. So here is my plan, and it's very near sighted so feel free to point in a logical directions for once this is completed.

Once I have cleared enough space in the garage I'm going to be bringing in the fuselage and stripping it right down. Peeling the old fabric off and then I will sand and wire-brush all the tubing, then go over with a fine toothed comb to try and spot any weak points (ie corrosion, heavy rusted out parts). I'm hoping this will be not too much of a chore.
After this I think it will be time to Prime and Paint? I've looked into this forum a great deal and found some awesome tips in this department. So I'm think epoxy primer, one red and one white, and then epoxy paint. If you are still here, Hank, I got the idea from you and I'm going to try and track down the harbour freight hobby airbrush. Was that a 3/4? I will probably go the Zinc Chromate for final fuselage paint as well for the frame. Anyone got any particular brands of epoxy primer and paints they prefer?

After all that I'll get another inspection from an AME buddy to see if he can poke any holes in my frame; hopefully not. I see some folks make a frame to hold and tilt there fuselage while they work on it. Anyone got the plans or a basic design before I start trying to reinvent the wheel?

This is where I am at anyways, guys. Sorry to have fallen off the map there. My dad and I are hoping to have it flying by the summer of 2017 and I feel that is a reasonable timeline. I will be sure to post pictures frequently.

cheers

[Hank Jarrett]

Re: Rebuilding 1938 BC-65

Howard,
Just a few suggestions.
First, the wood pieces that give the fuselage are called “Stringers”. Pay close attention to how they are attached to the fuselage. There were several ways used from cotton strips, to springs, lacing cord and welded fittings on the tubes. Also take lots of photos of how they attached to the wood or framing at the front ends. Putting all the “ginger bread” back together can get really confusing after all the tube work has been done! Make sure you photograph the cable runs too.
DO GET YOUR SPARS INSPECTED BY SOMEONE WHO KNOWS WOOD. Lots of times there can be a scratch along the grain from a nail hole in a rib that those who are low on experience will think is a split in the wood. Inspect the root ends really well. That si where you will most likely find splits and it is also the worst place for them. Any cross grain cracks or breaks are real spar killers but at least they are rare. Very common are corners being chewed by mice. They DO NOT necessarily mean the spar is no good.
Save your fabric as you remove it. I called them “plane pelts”. When you go to recover they will be invaluable for finding things like where to put holes in the fabric for cables to exit (Man can THAT be a hard problem!) Also provides a guide for where to put access holes and covers (a GUIDE! You CAN move them some and probably should when they have migrated following multiple recovers). They should be where you can actually USE them and a lot of mine were off a few inches making it impossible to reach things like the vertical tail wheel spring bolt in the tail.
As for stripping the tubes, I am NOT a big fan of wire brushes and sand paper. The Gold standard is still sand blasting, but you need to inspect and prime it as soon as possible after blasting. The surface will start to rust as soon as moist air hits it. After blasting the surface will look white, which is why I did my first prime coat in red epoxy. It was very easy to see where I had primed. I also did my own blasting (DON’T SKIMP ON THE SAFETY EQUIPMENT!!!!! You will need a suit and a hose respirator!) I blasted on 1½ bays at a time and immediately inspected and primed. When I blasted the next section I would blast some of the new primer off to get some overlap. If I found any cracks or damage I just stuck some masking tape over it prior to priming. After the primer was on I just pulled off the tape to leave the damaged area exposed for repair. Fix the damage and spot blast followed with more primer.
When the whole fuselage was red, I did a careful inspection for an missed spots (there always will be some) and that was the only place I used a wire brush, usually one on the end of a Dremel tool. Once I had a solid red epoxy fuselage I put the second coat of white epoxy primer on, again with the cheap HF air brushes. I did NOT use Zinc Chromate on top of the white primer, I had epoxy top coat PAINT mixed to match the original Zinc primer and painted the whole fuselage with that. Mine LOOKS like Zinc Chromate, but is actually Epoxy paint. I got my epoxy paint from Petit, who was making aircraft and boat epoxy at the time. It is REALLY good stuff and you won’t need nearly as much as they say if you use an airbrush.

As for a frame to hold your fuselage, all you need is 4 2x4s in a Tic-tac-toe pattern on the engine mount holes and a saw horse at the tail. You can rotate the fuselage into 8 different positions with that and it is as easy as it could be to reach inside the tube frame.

TAKE AND POST LOTS OF PHOTOS!!!! I took thousands’ and it wasn’t enough!

Hank

[HPsauce]

Re: Rebuilding 1938 BC-65

Thanks Hank,

I know that there is a man on our local airport that does industrial sandblasting. I always see high-boy trailers and logging trucks getting redone there. I wonder if he could do it. I'm just a little worried that a fellow who is use to really thick steel might go a bit overboard with a delicate aircraft frame. What type of material did you sandblast with? I've heard of people using acorn shells? Or somethin like that.

The stringers on the fuselage are lashed on with cord so I will probably do the same. Are all the tail services interchangeable between pre and post war models? I am missing an elevator. That being said, I have the older "flipper" style trim tab and probably want to go with one that's integrated into the elevator.

[Robert Lees]

Re: Rebuilding 1938 BC-65

I'd advise caution using industrial sandblasting companies. I have used them for aircraft stuff, but I paint strip first, and then go and talk to them, and advise them to use caution and low pressure. I usually take a sacrificial sample to assess their understanding.

Another option is to go to an automotive (or motorcycle) restoration facility...they tend to have a more gentle touch. Just as an example, I use this company local to me http://www.faircharm.co.uk/ and explaining the delicacy of steel aircraft structures, and they have done good work for me.

Another option is to use a soda-blasting facility, which can take paint off the thinnest aluminium without distorting it. BUT...(there is always a but, isn't there) you have to wash the soda residue away very thoroughly, and then acid treat the surfaces BEFORE you apply etch prime. It's quite easy to understand when you realise that soda is a strong alkali. Plus it's expensive (but they use baking soda, so it quite "green").

Hope that helps.

Rob

[3Dreaming]

Re: Rebuilding 1938 BC-65

While the flipper trim is a little in-effective, I would still choose it over trying to retrofit the trim to the elevator. The 1938 has a lower gross weight. In my opinion it should be kept light and simple. Leave the in elevator trim to the heavier later model airplanes.

[lfries]

Re: Rebuilding 1938 BC-65

I have limited pre war experience. After observing the pilot never use the trim I commented that using the trim might make life a little easier. He gave me the controls and it became obvious why he wasn't using the trim. There just wasn't any need.

[Hank Jarrett]

Re: Rebuilding 1938 BC-65

Lots of great comments and all I agree with. If you use a blasting company that does truck trailers it could damage your thin wall tube fuselage. I blasted my fuselage myself and used a 5HP compressor and pressure pot. The size of the compressor pretty much limited any potential damage. If I was to do it again I would go to a 10HP unit and still don’t think I would worry about it. The ship yard blasters here use equipment powered by huge diesel engines that I am sure would blow a fuselage apart. As Robert said, look for someone with a light touch. Trailer blasters would need to be very careful. I used regular blasting sand on my plane (NEVER use hardware store beach sand!!!!) for the steel but soda works GREAT on aluminum. I also have some Media blast (black plastic looking stuff, but haven’t tried it yet).
The tail surfaces are NOT the same. The structure is different as well as the type of steel (1010 and 4130). The bolts that hold them on can also be vertical or horizontal. DO NOT USE THE WRONG ONE and double drill holes!!!!!!
I have seen several planes that were converted from “Flipper” tabs to elevator tabs but I think it is pretty risky. First you need to make some complex mods to the fuselage and stab/elevators. Second, you are making a major mod to the TC that will require some significant paperwork, maybe even a DER sign off. You are changing the primary pitch control system and that is WELL beyond what we as owner/restorers should be messing with, which if the FAA catches you will cause you lots of problems. Finally, as Tom Baker said, you really don’t NEED much pitch trim. Set up and rigged right the flipper will work fine (most are NOT set up and rigged right when they “don’t work well”).
The 38 was a great, light, fun plane. I would put it back to original and enjoy the heck out of it. I have seen very few modifications that made one lighter and the lighter it is the better it will fly.

Thanks Hank,

I know that there is a man on our local airport that does industrial sandblasting. I always see high-boy trailers and logging trucks getting redone there. I wonder if he could do it. I'm just a little worried that a fellow who is use to really thick steel might go a bit overboard with a delicate aircraft frame. What type of material did you sandblast with? I've heard of people using acorn shells? Or somethin like that.

The stringers on the fuselage are lashed on with cord so I will probably do the same. Are all the tail services interchangeable between pre and post war models? I am missing an elevator. That being said, I have the older "flipper" style trim tab and probably want to go with one that's integrated into the elevator.

[N96337]

Re: Rebuilding 1938 BC-65

I had a J3 fuselage soda blasted and loved it!! It was easy to remove the coating that the soda leaves, and it's really nice not to have to worry about it flash rusting on the way home. That was in the 90's and it's still doing just fine with no adhesion issues, so must've gotten the coating off properly.
John

[HPsauce]

Re: Rebuilding 1938 BC-65

Ok, so the elevator trim conversion is a way bigger task then I imagined according to you guys. I only was thinking about swapping because it kind of hangs out and thought it may be vulnerable to damage from stones.

[HPsauce]

Re: Rebuilding 1938 BC-65

Speaking of this elevator trim, I am at the point where I need to remove it. I will be posting pictures this week; the airplane has come along a ways. The only things that need to come off the frame now is the landing gear and that little elevator fin trim tab. The thing is, I can't figure out how it comes off! It had two little pins that I pulled out thinking it just splits in the middle but no joy. Then again maybe it's been together for so long it's just stuck and needs a bit more persuasion. After all that's removed I have a person in town that has blasted airframes before with glass beads or walnut shells and the price is right so I'll get that done with him.

Once again, photos are coming! Just not on my computer.

[HPsauce]

Re: Rebuilding 1938 BC-65

Here are some pictures. most recent would show all the stringers and other wood out as well. Can't wait to have it blasted and painted. Then we will be making headway.