edited,
guys, so I have a World Models Midget Mustang (the last model I will buy from them). the slot on this fuselage for the Horizontal Stabilizer has "a ceiling", and the slot has a rather tight fit to the Stab. so if I apply glue to the slot then install the Stab a vary good amount of glue will be pushed away as the Stab is installed,

my friend told me to make divots down the middle of the slot (top & bottom) and use Gorilla glue because it foams,, I didn't like this idea because when this glue foams it has many-many bubbles throughout the glue.

I don't see any other way to install the Stab, can I get some comments about this ?

see page 7 in the link for reference,
A072.pdf

thanks big time guys
Jim

Take a popsicle stick, wrap it with a medium to fine grit sandpaper and use that to widen the slot slightly. Just make sure you don't angle the sides of the slot so the stab stays parallel to the wing. It won't take much to make the stab fit the way you want so be gentle with your sanding.

I'm not too sure about that one. A tight wood to wood fit is the most important thing for a strong glue joint. Assuming the parts aren't in a bind, opening it up will just require filling the gap with glue. That doesn't ever make for a good build.
It's ok if some glue pushes out. Press it into the wood so it soaks into the pores on both the fuselage and the tail. Wipe off what smears and press it into the joint after it's in place. Clean the residue with alcohol before it starts to cure.

no binding, it's a good fit, just a little tight, how about using "TiteBond" (3) wood glue, I know a lot of plane builders use it for framing. being thinner it will soak into the wood more than epoxy and have a longer work time than epoxy. but it will also be scraped off easier than epoxy as the Stab is being pushed into the slot

thanks for replying
Jim

I was going off of his comment that it was "tight". If it's a snug fit, I'd be leaving it alone as well but if it's tight enough to affect the shape of the fuse after it's installed, I'd lightly sand it as I stated above.

If it's balsa to balsa thin CA would be my choice.

David

Same here.

I would probably slide the stabilizer so it is about a glue-joint-width from being in place (i.e. most of the way).
Then apply a bit of slow-setting CA right along the joint, push the stab through so it's the same distance out on the other side, and apply another line of glue.
Finally center the stab in the fuselage (maybe even move back and forth a few times to get the glue spread out inside the joint) and let the glue set.

My bad. I thought the stab slotted in from the side...
I see from the manual it slots in from the rear (sorry, I can't post an image or link...)

Same basic suggestion. The idea is to get glue onto the stab and then distribute it between the two (hidden) surfaces.
In this case I would probably try to get glue inside the fuselage slot using a hypodermic needle or just carrying small bits from the glue dispenser tip into the slot on the end of a bit of solid wire. Then push the stab in place and align it.
Alternatively, you could try a modification of my first suggestion and slide the stab in dry, then slide it slightly to one side, apply glue, slide it to the other side, apply glue, and then put it in position.

A thin epoxy (like WEST System) would also work. You can clean excess off before it cures with denatured alcohol, if you get a little too much in and some of it oozes out.

If you're concerned about the joint's strength after that, you could apply a small fillet of CA or epoxy between the stab and fuselage-sides after the first glue has cured.

thanks guys for replying,

I will just have to find some thinner epoxy or epoxy with a longer working time.

I have been using epoxy since the 90s for many different things, I have found that one of it's biggest secrets is good mixing.
I have had very good luck with Devcon 2 Ton epoxy, but it's work time is rated for 30 minutes, but I mix very well and I find it's work time is really only 10 minutes or less.

mixing epoxy and applying it and thin aligning the horizontal stab correctly takes longer than 10 minutes, so I will get some that has a longer rated work time. .

thanks again for replying, you all conferred in what I was thinking

Jim

edited> laminating resin epoxy, OK, I see.
an hour working time sounds good, you have good time there to get things just how they need to be. I am going to look into buy some, most likely I will have to order it.
to add, most times I use epoxy I mix in some milled fiberglass to thicken it some. I have even used it with J&B Weld.

Jim

another reason why it's stronger, I believe that laminating resin is more pure than the glue is because the glue has thickeners in it. I had a wood boat back in the 90s so I read a lot about epoxys. but that was a long time ago, things may be different today

Jim

Agreed. Being able to choose fillers is major reason un-filled epoxies are so useful.

For wood joints, cotton fibers are the best generic filler. They have basically the same properties as wood (both are cellulose fibers), so the filled epoxy joint flexes very much like the material it's bonded to.
Fumed (or "colodial") silica is a great thickener, but it is very heavy and also very hard to sand.

The Gougeon Brothers WEST System® epoxy (westsystem.com/) is specifically designed for wood bonding. Its viscosity is higher than laminating resin, but that's due to the formulation and not fillers. In fact, WEST has some of their own fillers that I really like:

• 404 High Density
• 410 Microlight

One of the unusual features of both 404 and 410 is that you can add a very large amount of them to the epoxy. This is especially true for Microlight which I regularly add 4X by volume to epoxy. It makes a very smooth and low-density filler.
High Density has similar mixing behavior. It does not thicken the mixture anywhere the same as something like fumed silica (sometimes I will add "just a pinch" of silica to a high-density mix just to thicken it a bit when I don't want it to run).

One of the major advantages of epoxy (in general) is that it can fill a relatively large gap with good strength (in fact, it's important not to clamp an epoxy joint too tightly and squeeze out all the resin).

A trick for working with epoxy is that it cures much (much!) faster in a container than when spread out on a surface.

This is because when epoxy cures it gives off heat.
In a container the heat causes the mixture to react even faster, giving off more heat...
You get the idea...

Once the epoxy is spread out, its temperature is held essentially constant by the higher mass of the substrate.

Whenever I'm working on a large joint or surface, the first thing I do is pour out the epoxy from the container across the workpiece.
From that point on you have a lot more time to spread it out to the desired thickness since it's not curing as quickly as it would in the pot.

Another advantage of high-performance epoxies is that many of them have a number of different hardeners that will change the cure-time (and also usually the viscosity).
For example, WEST's 105 System has three hardneners: fast, slow, and super-slow "tropical".

Actually, there are FOUR:
205 is fast
206 is slow
207 is for coating or glassing
209 is extra slow
I have and use all four when building boats and planes

well I just bought some LockTite epoxy, it's set time is 1 hour, I will test it before I glue the stabs. if it works it will give me time to align the stab and clean up too..

I have West's #403 Microfibers thickener (thought it was milled fiberglass), I know it's not the best for everything, but it work well for me for the hobby

thanks for all the help and info
Jim

There's no need to add filler or strengthener to epoxy for this application. You are gluing balsa to balsa. As long as the glue joint is stronger than the surrounding wood, it's strong enough. All you need is a good wood fit and glue that will stay liquid long enough to let you get it put together.

I stand corrected,

I don't think I have much other than Fast and Slow (but I do use of the Gougeon bulk-dispensing positive-displacement pump, so that should count for something...)
westsystem.com/305-positive-displacement-pump/

For laminating WEST 105 isn't really very good (even with the super low-viscosity hardener).
You're much better off using Gougeon's ProSet (prosetepoxy.com/).

BTW, there are actually even other WEST 105 combinations possible by mixing G-Flex epoxy into a 105 resin/hardener mix:
.epoxyworks.com/index.php/mixing-gflex-with-other-west-system-epoxies/

^^^ What he said!

I'll bet the horizontal stabilizer in the OP's model could probably be attached by dry-fitting it and then applying a line of CA to the four 90-degree joints and letting it soak into the wood.

the fits are so good ^that's just what I was thinking.
too add to that, as I said, the horizontal slot has a ceiling as well as a floor, and it's fit is so good to the stab I think I could just drill 3 or 4 tiny holes in the slot's ceiling and add CA to glue the stab threw the holes, then add CA around the out side joints. then mount the vertical stab.

the photo shows the bottom of the slot for the vertical stab, I could drill the tiny holes threw for CA. I added the fake leather so you can see the 2 slots do not inter-join

Jim