dschroeder

My Feedback: (40)

as the subj says...anything wrong with using yellow carpenters glue for joining wing panles (40-60 sized planes) or gluing on vert and horiz fins?

JollyPopper

My Feedback: (6)

My experience has been that there are just a few places on a plane where eopxy is an absolute must. Joining wing halves is number one and wrapping a strip of fiberglass cloth about two inches wide around the wing before applying eopxy is even a good idea. The epoxy can then be heated and it will flow into the cloth strip and make the joint a permanent bond. Wings have folded up in flight because the wrong glue was used. The other places to use epoxy is where the firewall joins the fuselage and both vertical and horizontal statilizers. You don't want those surfaces coming loose in flight. There are other ways, I suppose, to do these things, but this way has proved effective for the last 60 years or so. It's a good idea to use 30 minute stuff in these places because 30 minute eopxy is stronger than faster setting epoxies. Slower setting stuff would be stronger yet, but 30 minute seems to be the best balance of setting time vs. strength.

Gray Beard

My Feedback: (-1)

The are a lot of places epoxy is a better choice and the wing center section is one of them along with the stabs. I just hate it when some of my favorite parts fall off, both body and planes. I also run my sheeting across the center section so there is no center seam so I don't require the glass strip.

Top_Gunn

My Feedback: (6)

I once had a stabilizer that was glued on with carpenter's glue pop off in flight. This was in normal flight, right after takeoff. I inferred from this that carpenter's glue tends to be a little brittle when dry. If so, vibration could cause it to crack.

That was with the original Titebond. There are newer formulas, which may be better. And it only happened once. But once is enough. I use epoxy for this now (as well as for wing joining and firewall attachment).

Lnewqban

Read more about it here:

http://www.airfieldmodels.com/inform.../adhesives.htm

Either CA or carpenter's are not good for gluing on vertical and horizontal fins for glow planes because they are not fuel proof.
Engine exhaust will sneak into those joints, modifying the glue consistency and bonding properties.

If your plane is electric and light, and gluing surfaces are plenty, you may get away without epoxy.

TFF

Not good. In high school, I helped my friend build a Falcon 56 but I did not know he used wood glue for the center joint and tape. Tower/ Kraft 5 channel radio and a K&B front intake/ rear exhaust .40. That rear exhaust engine blew the exhaust right on the wing joint, and on about the 8th flight while making a gentile turn, POOF! Houston we have seperation. The next plane he built, we made a 8" wing joiner, even though the plans did not show it because we were not going through that again.

sensei

If you have good fitting joints, then carpenters glue will work great, but if you have sloppy joints with gaps then carpenters glue is not for you. I use thin and medium CA in all my giant scale stuff, been doing it for years with no problems.

Tall Paul

I have no qualms using carpenters glue for every joint on the plane.
The joints must be made properly of course, with no relying on the glue to bridge any large gaps.
All of my many Kadets are constructed with carpenters glue, no CA or epoxy.

Rodney

No problem if properly done. Carpenters glue is usually stronger than the wood you are gluing together.

cfircav8r

My Feedback: (1)

The problem with carpenters glue is it requires tight tolerances and clamping pressure for a good joint, and yes hot fuel will deteriorate the glue over time. As long as it is clamped firmly and tight tolerances are followed and the A/C is fuel proofed as required then yes it will work. The up side of epoxy, if you use the right kind it is fuel proof and will fill the voids and still provide the strength needed for a good joint.

huck1199

For small, light electric planes yellow glue should be fine allowing for the joinery mentioned above.  For larger planes (3lbs and up) I would use 30 minute epoxy.

TimBle

a tubular or rectangular section called the wing tube carries the main load inconjunction with bolts or elastic bands. It matters not what glue you use here. Wood glue is fine if you allow for proper ccuring period.Same counts for the tailplane which is usually screwed down as well as bonded.Horizontal stabilisers do require high strength glue and epoxy fits the bill. Contrary to popular belief, the longer cure epoxies are more suitable not for higher bond strength but due to greater flexibility and vibration damping.

WhiteRook

My Feedback: (38)

EPOXY for important joints like wing , stab , fin . engine fire wall areas , i use titebond for everything else, because C A is to
messy to work with and the fumes burn my eyes

chevypower1930

So I've always wondered what is the reason to NOT use epoxy? haha, I mean it's not expensive and it's by far the strongest and best stuff for almost every part of an airplane, strongest as well as fuel proof, just my 2 cents, I'll always use epoxy especially for things like firewalls and joining wings

TimBle

Epoxy does nothing if it cannot penetrate the surface. Its just a surface coating in this case. expensive fuel proofer.


Often the wood in the arf around the engine has been treated with a fuel proofer so the Epoxy is not reinforcing anything as it cannot penetrate into the  wood!  I often  pour thick CA into gaps or cracks in the airframe. This works best here since it can flow into the gap. Thinned epoxy

Why do you need a fuel proof glue to join a wing where fuel will never reach. Unless you store the wings through submerging in methanol for months on end, what is the obscession with fuel proofing everything...?

Where epoxy is useful is area where high strength is required and the wood is not treated with fuel proofer and is relatively porous e.g. the landing gear area.

.

chevypower1930

Tim I am not saying the fuel proofing does anything for joining the wings, I'm saying that's just another great thing about it, or it has many great uses. Such as fuel proofing or epoxying in the firewall... and I've NEVER had a part come apart that was epoxied, ever... wings, firewalls, horizontal or fertical stabs nothin.. I also love using think CA too but i just think epoxy has more uses and is stronger especially as you said with porous material

TimBle

yes it is wonderful stuff.

of you take some balsa shavings and get them broken down by a wood chipper someplace, then mix it into your epoxy mixes, you'll have a filler that plugs gaps and has low voids. If you can apply pressure like vacuum bagging the wing, you'll never get the joint apart again.
Even Talcum powder or tiny glass bead filler improves the strength.

Yes its great stuff but often over kill for what we want to achieve. Remember there is little sence in the glue joint being stronger than the surrounding wood. That creates new weak points. Hence although I appreciate the wonderful substance epoxy is, we should apply a little thought into where we use it and why and what type.

I never did dispute that epxoy is fantastic

chevypower1930

Never tried that tim seems like it'd work great, I'm actually finishing up an escapade right now and I'm recovering from a major surgery so can't get out of the house to get my epoxy! haha and all thats really left is running the fuel lines and joining the ribs

TimBle

Chevy,

I hope you recover quickly, surgery not pleasant.

You will find once you  have your Escapade up and flying that it is a very well made and mostly assembled with CA glues. Don't be tempted to go over board with the Epoxy please

She flies great as she is but do wick some CA into the U joiner in the tail feathers.

chevypower1930

hahah okay Tim!

Yeah, I can't wait... I just bought a modded Stryker too that should run about 95, should be fun! haha can't wait to get to the flying field again, especially as I'm finally building my hangar back up! and now have swapped all my planes to 2.4 Spektrum technology

Lnewqban

For that purpose, you can also use carpenter's glue mixed with wood shreaded in a pencil sharpener.
It is lighter (epoxy is heavy) and sandable.

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chevypower1930

wow I meant running all the fuel lines and JOINING THE WINGS. hahaha not ribs

TimBle

ah I was wondering what the ribs was all about.

as Lnewqban says, wood glue with wood shavings as filler is also fantastic stuff. The wood shavings helps fill gaps so the glue has more to hold onto. makes woderfully flexible yet strong enough joints. Try it, you'll be amazed. You don;t need very long shavings either, quarter to half inch mix is adequate

smithcreek

My Feedback: (25)

If your "joints" are so poorly fitted you need that stuff a load of crap into them to bridge gaps you should redo your joints.