Hey guys,

How are you all doing ? I'm starting my build of Goldberg cub tomorow and just wondering where is recommended to apply ca glue and where is recommended to apply Epoxy? There must be some areas that require more strenght. Please let me know what you're opinions are, and it will make my built stronger and succesful.

Thanks

Epoxy is only required in high strength areas like joining wing panels,
firewalls and landing gear blocks. CA or aliphatic resin glues (wood glue)
is fine for everything else.

Mike Hammer

Your instructions should tell you specifically what to use where in each step that something is glued together. Typically, CA is used for CA hinges, not the other types, for hardening screw holes in wood from the servos, cowl, etc. Epoxy is used for anything structural. You didn't say if it was a kit or an ARF but if it's a kit I would suggest you PM RCKen with the same question if he doesn't see it and respond here.

Its not an ARF its a complete build at .40 Piper J3 Cub

Seb,
Read though the instructions completely. Goldberg kits usually have very good instructions, and they should tell you where to use which type of adhesive.

Ken

Seb, it is really difficult to mess things up, however you might go. However just think where you want strength. Of course that is in the areas of engine mounting, landing gear placement, gluing on tail feathers and wing mounting structure.

Those mentioned areas need the strength. Other structure will generally hold together with minimal glue.
Engine Mount: Use epoxy and a relatively slow one. I use 30 min. here. This area takes a beating all the time.
Landing gear: Same as an engine mount, but gets less beatings, although some really severe ones.

Wing and Tail mounting. Lots of pressures exerted here. Rolling high G turns can really flex the tail planes. (1:1 scale G load limits are less in rolling maneuvers than straight pull-out maneuvers due to this factor)
The wing supports the entire load of the aircraft weight. It needs strength especially in the center area and about to the 1/2 way out each panel. For example, Your model weighs 5#. You make a quick pull-out using -- let's say -- 10Gs, which now makes that wing support 50# weight. That's a bunch in a quick loading. [X(]
5 min. epoxy works in these areas, 30 min is better and you can do OK with using carpenter's glue. I use epoxy. (Heck we use to do it all with cellulose glue. Not so funny at times: )

One tip is that you can use CA to tack things, while all the interior touching joints are coated with epox/carp. glue. Saves a bunch of clamping and waiting. You have the parts secured well enough to just press on with the building and before you get to the flying field, it's all dry and ready to go.

Glad to see a BUILDER joining the modeler's fraternity. Let me see the finished work.

Right on thanks alot. i accually purchased the 30 min epoxy few weeks back and also have 15 sec Ca glue i thanks you guys for the support and i will be adding a post of my building progress

Everyone is right on with where to use epoxy (I only use 30 minute or better)
Along with firewall, landing gear blocks, attaching tail feathers to the fuselage and joining wing halves I also use epoxy for my servo mounts.

i im preatty much finished the tail and this is what it looks like... i did not use any epoxy should i have ? let me know what you think thanks !

Looks good.
You are fine but I would use epoxy to mount them to the fuselage.

and im wondering ... do i round off the t.e. of the stab ?... because i had to bevel the l.e. of the elevators

unfourtunatly my instructions only recommend CA wich i highly doubt so.. ill have to go with what people tell me

I've built my last few planes using CA only. I have really wrung them out and have had no failures of any CA joints so I feel confident in building with CA only. I have a old cub from about 15 years ago that I built with CA and the joints are still as strong as the day I made them so I think CA perfectly safe to use as the only adhesive. Each to his own.

I'd be sure to cover the surfaces before you permanately attach the hinges. Makes it a lot easier. I always use 30 min. epoxy to secure the tail sections so I have time to move it around a little in the alignment. Use CA and you have hardly anytime at all to adjust it for the proper alignment when attaching the stabilizer and fin to the fusalage.

And when you epoxy the surfaces to the fusalage make sure you epoxy wood to wood and not covering to covering. It will never hold.

Heres a few examples if it will give you any idea from a sig something extra. I use several pieces on some surfaces to keep the balsa from warping, or bending. Hope it helps you out in someway.

30 min is a good choice, It gives the epoxy a lot more time to soak in as opposed to 5 min. I'm also pretty sure that the 5 min epoxy isn't fuel proof.

Good luck!
Austin

yeh i am going to use the 30 mins epoxy for the requiered areas... i have some good CA as well... so if you find any other sites or pics that will help me out feel free to post them ...

Thanks

Seb23

Lots of pics in the thread below for some help.....

http://www.rcuniverse.com/forum/m_51...g%2Ccub/tm.htm

Thanks... ne one building a cub should go check it out

I mounted my OS .46 AX engine at a 45 degree angle so my stock muffler would work. Didn't want to buy a pitts muffler at the time. Clipped the wing also for better aerobatics and so it wouldn't look so gawdy with the full wing in my opinion.

When covering make sure the front part of the covering is over lapping the rear part so wind or fuel won't get up underneath the covering.

Cover from back to front on the fusalage and start on bottom, sides, then the top. On wing and tail covering start on the bottoms then the top.

you'll figure it out...good luck

mine looks silly but flys very well.....I build them to fly not to look at!

On your question about the trailing edges of your stabs.
They should remain sqaure and the leading egdes of your rudder and elevator should be beveled.

On your question about the trailing edges of your stabs.
They should remain sqaure and the leading egdes of your rudder and elevator should be beveled.

Yeh i stuck to that i just rounded off the trailing edge of the elevators, the trailing edge of rudder, leading edge of the fin and leading edge of stab