Author Topic: Gluing Wing In A Profile Fuselage (Read 2839 times)

Dick Pacini · « **on:** March 23, 2014, 08:19:20 PM »

What is the recommended way of gluing a wing into a profile fuselage without the glue (epoxy) being wiped off the center planking before the wing is all the way in?

I cannot remember how I used to do this many years ago. A possible solution would be to split and remove the bottom of the wing cutout and then glue and peg the removed piece back in place.

RknRusty · « **Reply #1 on:** March 23, 2014, 08:55:35 PM »

Dick, I usually paint the sheeting with epoxy and push it in a little too far so I can add some more glue to the other side, then pull it back into center. Then give it a quick hit with the heat gun so it flows. Wipe the edges clean and pin it straight. I think it gets good coverage like that. Hope that description makes sense. So far I haven't had one that came loose.
Rusty

Dick Pacini · « **Reply #2 on:** March 23, 2014, 09:10:49 PM »

That sounds like a good way. Of course, if I used CA, it isn't a problem.

RknRusty · « **Reply #3 on:** March 23, 2014, 11:44:51 PM »

Quote from: Dick Pacini on March 23, 2014, 09:10:49 PM

That sounds like a good way. Of course, if I used CA, it isn't a problem.

Yeah except it's such a rigid joint with no flex at all, I worry about it being like a stress riser along the joint. Plus unless it's a perfect fit with no gaps at all, which I never seem to get, epoxy fills in small gaps better. and unless you use extra hardener, epoxy(my off the rack stuff) sets with a tiny bet of flexibility. Nothing wrong with aliphatic glue either if you trust it for that job. For that matter I used Ambroid for most of my life, but that was with 1/2As. I'm an epoxyholic now though.
Rusty

Tim Wescott · « **Reply #4 on:** March 24, 2014, 11:29:31 AM »

I saw a method recommended here that I've used since, and it's worked great.

Get everything fit up. Then file 1/8" diameter half rounds in the wing saddle. Make at least two on top and bottom; more if you're paranoid. If you're really paranoid then take a gouge and mill a channel into the center of the wing saddle.

Then get the wing and fuselage fit up nicely, mix up some slow-cure epoxy, and use one of those disposable glue syringes to inject epoxy into the gaps. This will make a big dot of glue at each gap (or a short line, if you made channels).

I've done this on several planes, and have had no problems with wing joints.

john e. holliday · « **Reply #5 on:** March 25, 2014, 09:15:48 AM »

I know I will be put down on this, but I line my wing and fuselage up as best I can. Then I hit the joints that really fit good with CA. I seal one side of the joint with either Elmers Glu-All or Sigment. Make sure it is sealed. Then I turn the plane up on the wing tip after glue has set with the glue side down. Mix up some 30 minute epoxy and start putting it in the joint. Can only do one portion of the joint, top or bottom at a time so I can see if the epoxy is going into the joint. When the joint is filled/level I let it cure. Remember 30 minute epoxy takes a full 24 hours to cure. Now that I have it, I use Super Fil to do fillets and fill the low places in the wing/fuse joint.

Mike Lauerman · « **Reply #6 on:** March 25, 2014, 04:12:29 PM »

My younger brother knows it all. He glued the wing of his Sterling Mustang into the profile fuse with the old Testors C-ment... I told him to 'pre-glue', at least; but he knew better.
It cured for a week, he painted it, cleared it, and fuel-proofed all around the nose/doublers.

We went flying. The fuse parted with the wing, tried to slide off...but there was just enough 'bind' between the radiator scoop and the wing flap/pushrod that the fuse stopped about 30% Starboard, speed slowed to a 'fast hover'!
Our brother in law Carl was able to run out, grab the handle, and land it!
Engine running at a fast 4-cycle, plane came in slow, with about 40 degrees of fuselage-out-thrust! Didn't even break the prop.

Brett Buck · « **Reply #7 on:** March 26, 2014, 09:52:28 AM »

Quote from: john e. holliday on March 25, 2014, 09:15:48 AM

I know I will be put down on this, but I line my wing and fuselage up as best I can. Then I hit the joints that really fit good with CA. I seal one side of the joint with either Elmers Glu-All or Sigment. Make sure it is sealed. Then I turn the plane up on the wing tip after glue has set with the glue side down. Mix up some 30 minute epoxy and start putting it in the joint. Can only do one portion of the joint, top or bottom at a time so I can see if the epoxy is going into the joint. When the joint is filled/level I let it cure. Remember 30 minute epoxy takes a full 24 hours to cure. Now that I have it, I use Super Fil to do fillets and fill the low places in the wing/fuse joint.

I usually use only thin Hot Stuff and Aeropoxy light, so no put-downs here!

Brett

Mark Scarborough · « **Reply #8 on:** March 26, 2014, 10:18:06 AM »

I use thin CA myself,,
I generally align the fuse and wing,, put a tack where the wood touches,, ( we all know there will be some gaps, ,even small,,) then I recheck alignment,, another tack,, repeat for a couple times,, then I take scrap balsa from my junk drawer,, sand it to fit the gaps carefully,, and CA that in place,, takes a bit of time, but hey, balsa is lighter than epoxy,, and if CA will hold the ribs, spars, and shear webs,, pretty sure its good for the wing joint too,, but only if you use balsa filler,,

I did this on the avenger,, it has a fair number of flights,, several hundred,, and there is no sign of fatigue cracking or issues,,

Geoff Goodworth · « **Reply #9 on:** March 26, 2014, 07:04:23 PM »

I use CA to tack the wing in place near the LE and TE—where the two parts touch—then recheck the alignment.

If it's right, I push epoxy into the inevitable gaps—however small—with a popsicle stick and encourage the epoxy to flow through the gap with a heat gun.

I then put the model back into the jig and allow the epoxy to cure.

Once cured, I repeat the exercise with the epoxy from the other side and again, back in the jig until cured.

This has worked just fine with fuselage planks 3/8" and 1/2" thick, pin routed and laser cut.

Paul Smith · « **Reply #10 on:** March 27, 2014, 11:39:39 AM »

I like to fixture the wing & body, then use CA.
Then fill any gaps with scrap balsa.
Finish with warmed epoxy mixed with micro balloons in four operations using gravity as your friend.

In the long run CA alone doesn't get it done. In time the fuel will disolve it.

Jim Thomerson · « **Reply #11 on:** March 28, 2014, 04:35:32 PM »

I do something similar to said above. I tack the wing in place with CA, then carefully close the line between wing and fuselage on the outboard side with Sigment. Once this is dry, I hang the airplane from the leadouts such that the fuselage is level. Then I use slow cure epoxy applied to the inside joint. I use a hair dryer to thin the epoxy and drive out any air bubbles. I make pinholes in the wing sheeting and in the fuselage first. I've never had one break. A friend once gave me some epoxy for finishing fishing rods, which had some flex when set. I used it on slow rats and liked it.

Author Topic: Gluing Wing In A Profile Fuselage (Read 2839 times)

Dick Pacini

Gluing Wing In A Profile Fuselage

RknRusty

Re: Gluing Wing In A Profile Fuselage

Dick Pacini

Re: Gluing Wing In A Profile Fuselage

RknRusty

Re: Gluing Wing In A Profile Fuselage

Tim Wescott

Re: Gluing Wing In A Profile Fuselage

john e. holliday

Re: Gluing Wing In A Profile Fuselage

Mike Lauerman

Re: Gluing Wing In A Profile Fuselage

Brett Buck

Re: Gluing Wing In A Profile Fuselage

Mark Scarborough

Re: Gluing Wing In A Profile Fuselage

Geoff Goodworth

Re: Gluing Wing In A Profile Fuselage

Paul Smith

Re: Gluing Wing In A Profile Fuselage

Jim Thomerson

Re: Gluing Wing In A Profile Fuselage