Looking for thoughts on balsa WW2 models........

[bdefen]

Show us the Storch as you build it. Ask questions if you hit a snag.

Got my Dumas balsa Storch started late January. Have pretty much finished the assembly of the wing, horizontal/vertical stabilizer, and fuselage. Since a flying model is not my primary goal (but I may give it a try), I've been adding reinforcing gusseting, extra stringers, and some solid sheeting to reinforce or replace the very delicate 1/16 square stringers. I've fractured a few with an errant grip hear and there. My reinforcing has added some weight, but it's certainly a lot sturdier.

The wing was an enjoyable challenge, mainly in setting the dihedral, and bending and installing the reinforcing wire. Until it's covered, installed, and braced, the wing will be somewhat delicate. My rather rough gusseting of the vertical stabilizer will detract from the overall look of the piece when the tissue is shrunk and painted. I'm thinking of perhaps covering its framework with heavy paper or light cardstock before placing the tissue in the hope of hiding my rough gusseting. I could certainly use any suggestions or advice here.

Lots of sanding left to do. After placing the tissue, the next big challenge will be bending the .014" wire to the proper shape for constructing the landing gear. That step occurs after the tissue covering, before assembling the wing, fuselage, stabilizer, etc.

Oh, I couldn't find any Titebond 3 in a quick shopping errand, so I went with Elmer's Wood Glue Max.
Seems fine.

Thanks in advance for any advice.

 

[Wurger]

 

[Casor]

For the record, there are virtually no flight loads on the wing root on the Storch when the aircraft is in flight. If you look where the struts attach to the wing, most of the wing's lifting surface is outboard of them. Therefore, there is a net down force at the root when in flight. The wing root on the fuselage is there only to position the wing and to keep it from moving around, not to absorb any flight loads. On the real one, there is only a retractable pin at the LE and a hinge at the TE holding the wing panel to the fuselage. No dihedral bracing, no "extra strong" fuselage or root structure, just a light framework.

The main struts on the Storch do all the work.

 

[bdefen]

For the record, there are virtually no flight loads on the wing root on the Storch when the aircraft is in flight. If you look where the struts attach to the wing, most of the wing's lifting surface is outboard of them. Therefore, there is a net down force at the root when in flight. The wing root on the fuselage is there only to position the wing and to keep it from moving around, not to absorb any flight loads. On the real one, there is only a retractable pin at the LE and a hinge at the TE holding the wing panel to the fuselage. No dihedral bracing, no "extra strong" fuselage or root structure, just a light framework.

The main struts on the Storch do all the work.

If the balsa model design and "engineering" is anything close to a real Storch, (at least before my added gusseting and bracing) your point is well taken, and very informative. With regard to the balsa model, I guess the reinforcing wire is there the hold the angles until the tissue skin, wing mounting, and bracing are secure. And the model's main struts are the biggest pieces of wood in the kit. A true "space frame". The Storch is the product of true genius. Thanks for your help and information.

 

[Casor]

If the balsa model design and "engineering" is anything close to a real Storch, (at least before my added gusseting and bracing) your point is well taken, and very informative. With regard to the balsa model, I guess the reinforcing wire is there the hold the angles until the tissue skin, wing mounting, and bracing are secure. And the model's main struts are the biggest pieces of wood in the kit. A true "space frame". The Storch is the product of true genius. Thanks for your help and information.

Yes, the same theories apply and have been borne out by the RC flying models I have made of the Storch. The struts have to be strongest link in the chain, nothing else really matters. OK, maybe the wing spars. I mentioned it as it is also an avenue to save weight on a rubber model.

 

[drgondog]

I stumbled upon this thread but it brought back memories of building only balsas and balsa/plastis ranging from Berkley to to Monogram rubber propeller driven to Monogram Speedee Bilt to Gullows plus several scratch as I got better. I moved to plastic and stopped when I just didn't have that kind of time anymore about 30 years ago

The last one broke my heart at age 17. Berkley B-17 (1" to 1ft scale) R/C four channel that I last saw catching Santa Anna winds heading west over the ocean at Pacific Palisades. I probably devoted 100+ hrs to the build, detailed the panels, 4x K&B 29s. It was trimmed and climbling steadily. I won a stand-off scale with that one in 1959

I was also into control line and combat with my favortite Reactor ( I think?) flying wing - it was about that time that I started playing a lot of golf and shooting skeet/trap.

I still have two 1/7th scale Top Flight (plus one Royal) P-51s in our utility barn that have been idle for 20 years - will give to my youngest grandson.

Question - my old 'go to' was Ambroid for wood and testors for plastic. What is recommendation for either today?

 

[Casor]

I stumbled upon this thread but it brought back memories of building only balsas and balsa/plastis ranging from Berkley to to Monogram rubber propeller driven to Monogram Speedee Bilt to Gullows plus several scratch as I got better. I moved to plastic and stopped when I just didn't have that kind of time anymore about 30 years ago

The last one broke my heart at age 17. Berkley B-17 (1" to 1ft scale) R/C four channel that I last saw catching Santa Anna winds heading west over the ocean at Pacific Palisades. I probably devoted 100+ hrs to the build, detailed the panels, 4x K&B 29s. It was trimmed and climbling steadily. I won a stand-off scale with that one in 1959

I was also into control line and combat with my favortite Reactor ( I think?) flying wing - it was about that time that I started playing a lot of golf and shooting skeet/trap.

I still have two 1/7th scale Top Flight (plus one Royal) P-51s in our utility barn that have been idle for 20 years - will give to my youngest grandson.

Question - my old 'go to' was Ambroid for wood and testors for plastic. What is recommendation for either today?

Depending upon the application, I use thin or medium CA, titebond III wood glue or epoxy for wood. Plastic, depends on what the items are. For canopies, I use formula 560 which is a white glue that dries clear, otherwise it's CA or the thin model plastic cement that welds the pcs together.

 

[Snautzer01]

I still have two 1/7th scale Top Flight (plus one Royal) P-51s in our utility barn that have been idle for 20 years - will give to my youngest grandson

Now now... and you did not share a picture with dear old us??? Shame on you.

Oh... the P-51... not the barn.

 

[drgondog]

Now now... and you did not share a picture with dear old us??? Shame on you.

Oh... the P-51... not the barn.

Here ya go

 

[Snautzer01]

Cool.

 

[Ivan1GFP]

Hope this question is not a distraction:
It has been decades since I built anything out of wood.
What is the best glue to use for a flying model and what is the best glue to use for a static model?

 

[Wurger]

What is the best glue to use for a flying model and what is the best glue to use for a static model?

My workmate always says that the best glue is just the one you may buy cheap in the nearest shop.
Actually there is no the best glue for the flying model or the static one. For sure the one for the flying kites needs to be light in its weight and of the great durability and resistance to the moisture. The static model doesn't require a glue of such properties although the waterproof feature is also welcome. There is a lot of them offered at the market. All it depends on the particular model parts you want to stick together. Also on the kind of the woods used etc ... Just my opinion.

 

[Casor]

For flying models, I like water based Titebond III which is strong and waterproof. Parts should be clamped. weighted or pinned while it's drying. The stuff is seriously strong and most of the weight evaporates. Then there is medium and thin thickness cyanoacrylate (CA) which is stong and dries fast. High stress areas I like 30 min epoxy, sometimes mixed with 1/16" glass strand to form a composite matrix which, to a point, winds up being stronger than just the epoxy alone.

 

[PNW Guy]

This is one of my favorite YouTube channels. Maxfiart scratch builds unique rubber powered free flight models. Many videos include the build process and all have excellent flying sciences.

https://m.youtube.com/@maxfliart/videos

 

[Casor]

This is one of my favorite YouTube channels. Maxfiart scratch builds unique rubber powered free flight models. Many videos include the build process and all have excellent flying sciences.

https://m.youtube.com/@maxfliart/videos

Yes, Tom Hallmam is one of the most talented FF modelers in the world.

 

[special ed]

Glues are discussed earlier in the thread. I still use Titebond III for almost all balsa work, however larger structures I use C-A instant as a sort of tac weld to keep all in alignment. The C-A is plenty strong enough by itself, but being a belt & suspenders type, I go over the joints with Titebond III. I also have a mist sprayer which I mist spray water on the wet freshly applied Titebond to allow better penetration in balsa. I almost never use epoxy any more because of weight, as Titebond works as well on wood. Metal to wood needs epoxy, such as landing gear wire.

 

[Skyediamonds]

Here ya go

Big Beautiful Doll builds into a beautiful model, if done properly. Here's my wooden Guillow's P-51D model of Big Beautiful Doll. I posted several build threads.

The fuselage was infilled with balsa & wings sheeted over. Then the model was covered in aluminum foil.

I used mostly CA glue but I also used white Elmer's glue in areas that in needed wiggle room before the glue dries.

 

[Ivan1GFP]

Glues are discussed earlier in the thread. I still use Titebond III for almost all balsa work, however larger structures I use C-A instant as a sort of tac weld to keep all in alignment. The C-A is plenty strong enough by itself, but being a belt & suspenders type, I go over the joints with Titebond III. I also have a mist sprayer which I mist spray water on the wet freshly applied Titebond to allow better penetration in balsa. I almost never use epoxy any more because of weight, as Titebond works as well on wood. Metal to wood needs epoxy, such as landing gear wire.

I found a pretty good detailed discussion on different wood glues in a RC aircraft forum yesterday.
Way back when I last built (attempted) a balsa kit, it was with Testors Wood Cement. It worked well enough, but I figured there was something better by now. Seems like everything has its different characteristics and issues.

It seems that you build for 0.049 powered control line models. A 049 relatively speaking is a lot of power and weight is not nearly as critical.

 

[special ed]

Through the 1950s & into the 1960s the model glue for balsa was Ambroid cement. It was a common cement (glue) in tubes and cans for canoe repair. It dried strong and waterproof but usually dried as a web on 90 degree joints. I have found when recovering or restoring old flying models built with Ambroid, if one breaks the surface (skin) on the 90 degree joints, a perfect pocket is provided for a drop of C-A instant bond which penetrates the old dry balsa and makes a really hard, light piece. Regarding model size, I still build some .049 powered models but most are any where from .15 through .45 powered, so wingspans from 18 or 20 inches to 45-50 inches. I tried to convince my late brother in law that it was easier to fly the larger models controlline than the smaller .049 size models. When he passed, my sister awarded me his models and parts. He was in the hobby because of his older brother and among what I got was several incomplete kits of Sterling model company's profile P-51 balsa model. I have guessed that when the brothers crashed, they bought another kit to use the parts for repairs, rather than a complete new build. I have made the missing parts to complete four profile P-51s. Finish paint coats are on but, just as you all are with your kits, the insignia details await.