LonnieMcc

Hey guys,

I am currently building a Balsa USA Fokker DVII 1/4 scale. I have all four of the outer panels completed as well as the lower center section.

Basically now I am at the point of joining them. But I have a question as to how they suggest doing this.

In the manual it says that once everything is lined up to use thin and think CA. Wouldn't it be better to use epoxy??

I only ask because I have not used this method of joining wing panels.

Also, would it be a good idea to fiberglass the entire center section?

Edwin

My Feedback: (2)

I havent built this plane but I would use 30 min epoxy on any structural or major joining location.
Edwin

stevenmax50

My Feedback: (1)

I would concur with Edwin.  Those are high load areas.

MTK

Let me suggest Gorilla glue. It will fill the imperfections in the joint. Then a layer of 3 ounce glass over each joint. I usually install the glass on bias because it is 40% stronger that way and stiffer, but either way it will be fine.

Either 1 coat laminating epoxy for the glassing or 2 coats clear epoxy paint work fine.

LonnieMcc

Hey guys thanks for the help.

I figured epoxy would be better to use, just wanted to be sure that would be best.

vicman

My Feedback: (10)

I'll give a second vote for gorilla glue. Have been using it for years to join wing panels with zero failure.

The only thing I would add is to use the woodpecker also. The dents in the wood act like little rivets when the GG kicks and adds a tremendous amount more surface contact for the glue.

You will need to do a very good job clamping the panels together, that foamy action will push the pieces apart if you aren't careful.

Gray Beard

My Feedback: (-1)

Why not phone BUSA and ask them. They are very good at answering questions about any of there kits. Perhaps one of the best and there kits are outstanding. If anyone knows it will be the designers. Your going to love the D-VII, best WWI Bipe I have flown but I haven't built the kit.

RCKen

My Feedback: (9)

I'll second what Gray Beard has said here. I've built many Balsa USA kits over the years and I can tell you that they are probably one of THE best companies out there at designing planes, and there instructions are usually spot on with how to biuld the plane. Now that doesn't mean that there aren't mistakes from time to time with an instruction, but when there is BUSA will step up and make any corrections that are needed. I've found on the many BUSA planes that I've built that following the instructions in the manual is usually the best recipe for successfully building the airplane.

I am currently building the D-VII myself, although I haven't gotten to the step you are on yet. However, I have gone through the manual and made notes on things I will do when I build. On this step I plan to use epoxy. Now in light of my last statement you might ask me why I'm not following the very instructions that I said were so good, but I assure you this isn't a "gotcha moment" here. I am changing from using CA and plan to use epoxy for this step, and the simple reason why is because I don't use CA when I build a plane. Well, I almost don't use CA. There are a few steps that require CA when building and those can't be changed out, things like CA hinges and hardening threads cut in wood for wing bolts and such. But other than those types of steps I have eliminated all CA's from building an airplane. So my choice for not using CA is personal. I would say that you could follow the instructions and use CA here and you will be just fine with the strength of the wing. Remember that this isn't a new kit and there have been quite a few biult, and if there had been a problem with this method of buidling we would have more than likely heard about it by now. So you'll be fine using the CA and following the instructions.

As a side note on not using CA when building. I quit using it years ago and I feel that the quality of my builds has gone up dramatically. I quit because I didn't want to develop the severe reactions to CA that many people have over the years. I've talked to doctors and chemists about CA and what happens when you use it, and it can be a bit scarey. CA kicks and reacts when it comes in contact with moisture. So any vapors that enter the body (a pretty moist environment indeed) will react with the tissues in your body. At first most people's bodies can handle these reactions without many problems. But repeated exposure can cause the body to not deal with these reactions and over time they can become severe. I've seen people that have trouble breathing for days after a very small exposure CA fumes. With the amount of reviews I was doing years ago I choose to eliminate as much CA usage as I could. When doing a review we follow the instructions that come with the plane, so if they call for using CA we use CA. Since I was getting exposure to CA with my reviews I choose to not use it on my builds. Now that I'm not doing reviews any longer I still don't use CA because I feel my builds are better by NOT using it. The adhesives I use the most when building are simple Elmer's Carpenter's Wood Glue and epoxy. I have found that when using wood glue I have more time to get the joints right before the glue sets, and those joints are sandable now as wood glue doesn't set hard like CA.

Anyway, I'll get off my soapbox now!!!!

Follow the instructions and you'll do fine

Ken

mattnew

My Feedback: (2)

If you use CA you might be ok in this section.

If you use other glues and a combination of fiberglass you'll almost definitely be ok.

Personally i'd probably use titebond and then fiberglass the center section. Glue strengths on wood/wood joints go PVA glue -> epoxy -> polyurethane glue from strongest to weakest although in ANY case, the glues are all much stronger than balsa and plywood, so your wood will break first. No scientific tests I've found online test CA at the same time as these other glues so i can't comment on CA strength here. From crash experience though, I know my CA joints usually remain intact and the balsa around the joints break so I'd think its probably perfectly fine as well.


glue strength reference: There are a number of these that have been done with results available online, but the below is what I have bookmarked.
http://www.oldbrownglue.com/pdf/HowS...urGlue_FWW.pdf

jeffEE

My Feedback: (5)

I have built 3 Balsa USA Fokker DVII's. I used CA on the wing joints on all 3. My first I lost in a mid air, but the second one I have 2 years of flights on it. Not a problem. I did not use fiberglass, or epoxy. You of course are free to do it however you want. But I have never had any issues. Just my 2 cents.

P.S. You are going to love how this bird flies!

LonnieMcc

Hey guys,

Thanks for the responses. I was going to call BUSA today, but wasn't able to. I may go with the epoxy just because I will feel more at ease doing that.

I may start a build thread on here, in case I need a little more insight on the build. lol

So far everything is turning out great. It seems this one is going better than my CG chipmunk I built.

And Jeff, that is one beautiful bird. I am still undecided on what scheme I want to use. I was thinking of one from the Jasta 18 group. I just need to find some documentation on that group so I can make a final choice.

Any ideas which book would be best to use??

RCKen

My Feedback: (9)

I'm planning on doing my D-VII in Ernst Udet's "Do Doch Nicht" (Definitely Not You) scheme.

Tepid Pilot

Shortly after the release of the kit I built the Sig Kadet LT-40 for the most righteous but now defunct RC Report magazine. I was quite alarmed that the instructions called for only thin ca to be used for joining the wing panels. Thin ca to join a 70" wing? Egad! But one of Gordon's stipulations for test reports was that the instructions should be followed, so follow them I did.

I liked the LT-40 so well that I kept it. It must have had close to 1000 flights, give or take a few, and the wing held fast. The ultimate demise of that particular plane was caused by the vertical fin parting company with the fuse. Despite the resulting smack into a concrete runway the wing held fast.

I'm just sayin'.

TP

Gray Beard

My Feedback: (-1)

There is nothing wrong with CA glue as far as holding/bonding balsa parts. I find it as good as any of the other glues and still buy thin CA in 8 ounce bottles because I use so much of it. I did develop a CA reaction very early on with it. That was due to the small confined space I was working in and it was completely closed up during the winter while I was working. The way I build these days I'm OK with it but even my wife can tell when I have been using it for sheeting.
I know a lot of builders that have gone back to just Elmer's wood glue or titebond. On my present build I have been using a lot more Sigment then I have in the past. Like Ken, it gives me a lot more work time so things do come out a bit better. I have gotten too much warping with water based wood glues and the Sigment doesn't have that big problem. Set time is still pretty fast.

Edwin

My Feedback: (2)

Its a cost thing for me. To me, CA is too expensive to use so much. My main build glue is titebond, 30 min epoxy. CA is used for small repairs and fastening points.
Edwin

foodstick

This plane is a KILLER bird ! Here is my take .. they will all work, but IF you use the Gorilla glue be dang sure you know how it expands, or stand there and wipe it because it goes crazy !

As for the glassing the center joint.. I am not sure it matters, with the inner and outer cabanes /struts , I really don't think the load on that joint is as extreme as if it was a one piece monoplane wing.

jeffEE

My Feedback: (5)

For Jasta 18 planes I would go with Osprey Publishing "Jasta 18–The Red Noses " by Greg Van Wyngarden. It is full of great information on the Jasta 18 fighter group. Plus lots of photos and color profile and plan forms for excellent documentation. This book is number 40 in the Osprey “Aviation Elite Unit� series and it provides combat history for pilots such as Rudolf Berthold, Josef Veltjens and Paul Strahle and August Raben to name a few. I have not looked to see if its still in print. Nice thing about the Balsa USA DVII is that so many of us have built one, there is a lot of help out in RCU land.

RCKen

My Feedback: (9)

Do you know if there are any that give more data on Ernst Udet and the planes he's used?? I've looked a little, but haven't found much yet.

Ken

jeffEE

My Feedback: (5)

If you want to read about Ernst Udet, two books are indispensable. Udet wrote his own episodic biography entitled Mein Fliegerleben, published in 1935. It has been twice translated into English. In 1937 a British edition, translated by Kenneth Kirkness, came out as Ace of the Black Cross. You may be able to find this old book via used book outlets or websites. However, in 1970 a new translation by Richard K. Riehn was published in the US entitled Ace of the Iron Cross. This came out in several paperback editions and should be easy to find on ebay or from used book outlets. I think the translation is very good.

Udet wrote (or perhaps dictated) a rather short and propagandistic wartime paperback memoir entitled Keuz wider Kokarde, published in 1918. It is very hard to come by and is rather expensive on the used book market.

The best biography of Udet was written by Armand van Ishoven, entitled The Fall of an Eagle; The Life of Fighter Ace Ernst Udet, (William Kimber, London 1979,ISBN 0 7183 0067 X). It really is a superb biography, well researched and nicely illustrated.

And of course the debate goes on about the DVII. Was it red or not?

RCKen

My Feedback: (9)

Trust me, in the research I've done so far I've definitely seen this debate more than once. I'm going to come down on the side of it's red, because that's how I want to paint it!!!

Ken

jeffEE

My Feedback: (5)

Then red it is. After all it is YOUR plane. And Udet did call one of his planes a lovely red bird.

Granpooba

My Feedback: (5)

DITTO !! Any major structural joint requires epoxy !!

TonyBuilder

My Feedback: (11)

Once you get a few builds under your belt you will develop a build style. Recommended glues is just that. You can go with yellow glue instead of CA, or gorilla glue, epoxy or what ever you want. CA is a quick instant gratification but it is very brittle, it is ok for most soft balsa applications and tacking, but epoxy and yellow glue is much stronger and sands better to.

mattnew

My Feedback: (2)

meant as a serious question and not to be antagonistic. Why is this so?

mattnew

My Feedback: (2)

Too add to my question.. I've always up until recently believed this as well. But there are now numerous glue joint-strength tests that show that epoxy is actually weaker than other glues.... I'm trying to understand if I'm missing something here.