Glues for motor mount installation

[Motörhead]

Hi all,

Just wondering what sort(s) of glues you use for installing motor mounts into low-power rockets. So far I've been using Selleys PVA (white glue) and the motor mounts in all my rockets have been holding up very well.

Should get some interesting answers I imagine.


Cheers ...... Pete

 

[Micromeister]

Micro's to Clustered mid powered LMR's are generally installed with Carpenters yellow or brown wood glues. sometimes on big heavy clusters I'll reinforce the lower CR with an epoxy fillet after the yellow has completely dried

 

[Zack Lau]

White glue is a good choice for LPR. Wood glue is stronger, but may grab in the wrong spot. The shinking of wood glue can also distort body tubes. This is a problem with my scale birds which are carefully painted to look nice.

 

[Rick Lindsey]

I use Elmers yellow wood glue for my LPR construction and I've been happy so far. I'll probably use that same bottle of glue for my mpr stuff too, until it runs out, at which point I'll probably buy some titebond.

-Rick

 

[Micromeister]

Don't want to disillusion you Zack but all glues with the possible exception of SOME epoxies shrink. White and Yellow Charpenters glues have the exact same shrink rate but as you mentioned yellows can grab a bit quicker if you don't mind what and how your doing it. Tite-Bond-II or III Brown carpenters glues have a slightly different formula that can shrink a bit more and is a grab hazzard
Sometimes we generalize things a bit too much.

Another of my all time favorite Glues for LPR/MPR models is Ambroid cement. Sworn by for decades in the flying model airplane hobby, hot fuel proof, stays flexable after decades, and very hi bond strength.
Only draw backs are " the smell" and it draws bodytube (shrinks) during drying. It's still a frequently used item in my shop because of it's bonding strength and longevity on many of my Scale subjects.

 

[Rick Lindsey]

How well does the ambroid bond to plastic?

-Rick

 

[uncle_vanya]

Originally posted by Micromeister
...Tite-Bond-II or III Brown carpenters glues have a slightly different formula that can shrink a bit more and is a grab hazzard...


Another of my all time favorite Glues for LPR/MPR models is Ambroid cement. Sworn by for decades in the flying model airplane hobby, hot fuel proof, stays flexable after decades, and very hi bond strength.
Only draw backs are " the smell" and it draws bodytube (shrinks) during drying. It's still a frequently used item in my shop because of it's bonding strength and longevity on many of my Scale subjects.

Amen on the "grab" of Titebond. I love the stuff but it can make you cry when you try to insert one tube into another (coupler) and it seizes too soon.

As for Ambroid. I have some that I have been meaning to try. I haven't had a chance yet. What's the drying time?

I also like Polyurathane glue for specialized work. It's a foaming mess - so I only use it where it will not show but it grabs plastic very well where other things do not.

 

[Rick Lindsey]

Originally posted by uncle_vanya
I also like Polyurathane glue for specialized work. It's a foaming mess - so I only use it where it will not show but it grabs plastic very well where other things do not.

Unfortunately the places I need to bond plastic will show .

-Rick

 

[Stymye]

titebond III has much less grab than the other titebonds with a longer "open" time , by far my favorite for low-midpower.

they saw a need for it and improved on it.
I'm suprised more people here don't use it, because it's also stronger than Gorilla type glues.

 

[DaveCombs]

Usually Titebond II or Weldbond for me. But Weldbond is very flexible, so it may be appropriate for attaching fins, but it's REALLY hard to sand because it retains most of the flexibility.

 

[vicious-peanut]

On my rockets I use a mixture of expoxy, tacky glue and CA. For motor mounts, it is always epoxy.

 

[Rick Lindsey]

Originally posted by Vicious-Peanut
On my rockets I use a mixture of expoxy, tacky glue and CA. For motor mounts, it is always epoxy.

Wow, epoxy on an Alpha?

-Rick

 

[Micromeister]

Originally posted by Rick Lindsey
How well does the ambroid bond to plastic?

-Rick

Rick:
Exactly what kind of "plastic"?
it's an OK plastic solvent cement for Styrene and acrylics, no good at all for some modified acrylics, polycarbonates and other types.
Not my first choice for bonding plastics but very useable on the two types mentioned above.

I also like Titebond-III, it's got a bit longer grab time the TB-II and as stymye mentioned as strong as the Urethaneglues without the clamping (expanding foam) problems.

 

[Rick Lindsey]

Originally posted by Micromeister
Rick:
Exactly what kind of "plastic"?
.

A canadian arrow tailcone

-Rick

 

[Micromeister]

the Arrow tail cone is a blow molded styrene, ambroid will work fine, but be careful it well deform (mark, mare, semi melt) anywhere it touches the plastic so be very delibrate where it is placed.
What parts are you adding to the tail cone?

 

[cjl]

I love titebond III, and use it exclusively for all non-plastic bonds in LPR.

 

[vicious-peanut]

Originally posted by Rick Lindsey
Wow, epoxy on an Alpha?

-Rick

Oops, the Alpha uses Wood Glue.

 

[Rick Lindsey]

Originally posted by Micromeister
What parts are you adding to the tail cone?

Nothing, just gluing it into the body tube and gluing the fins to it. Probably filets along the cone/fin joint so the slot isn't left unsecured.

-Rick

 

[Micromeister]

Originally posted by Vicious-Peanut
On my rockets I use a mixture of expoxy, tacky glue and CA. For motor mounts, it is always epoxy.

For goodness sake why? For LPR and MPR rockets a decent double glue paper/paper or paper/wood joint with plain old elmers is stronger then any forces you'll be able to apply to it. Well expect sitting on the model
If you looking for Pretty fillets or a little extra bounce recovery strength Then an epoxy filler, fillet or reinforcement is the way to go.
CA's are great for tacking and VERY Short LIFE competition models but the stuff becomes increditably brittle over time and will help you re-kit your models in flight in a year of so

Most of the models you'll see me flying or posting pics of are generally Yellow glue construciton with some having epoxy finish fillets. Many of these models are still flying after more then 30 years, Sometimes we really do overbuild in this hobby.
Remember please when it comes to LPR and mid range MRP modeling Lighter is always better for both performance and longevity
Hope this helps.

 

[vicious-peanut]

Originally posted by Micromeister
For goodness sake why? For LPR and MPR rockets a decent double glue paper/paper or paper/wood joint with plain old elmers is stronger then any forces you'll be able to apply to it. Well expect sitting on the model
If you looking for Pretty fillets or a little extra bounce recovery strength Then an epoxy filler, fillet or reinforcement is the way to go.
CA's are great for tacking and VERY Short LIFE competition models but the stuff becomes increditably brittle over time and will help you re-kit your models in flight in a year of so

Most of the models you'll see me flying or posting pics of are generally Yellow glue construciton with some having epoxy finish fillets. Many of these models are still flying after more then 30 years, Sometimes we really do overbuild in this hobby.
Remember please when it comes to LPR and mid range MRP modeling Lighter is always better for both performance and longevity
Hope this helps.

On the Aspire I used Epoxy on the fins because It should be breaking the sound barrier with the G80, so I just wanted a good bond but the fillets were wood glue. Plus I worried that the wood glue wasnt strong enough for the other uses. Apperently it is, so I will cut down on the epoxy.

Oh, and the CA I only use for when I fold the shock cord mounts on the Estes kits, since I dont want to wait hours for the elmers or wood glue to dry.

 

[Micromeister]

Originally posted by Rick Lindsey
Nothing, just gluing it into the body tube and gluing the fins to it. Probably filets along the cone/fin joint so the slot isn't left unsecured.

-Rick

amboid should be fine then, just be careful glueing the fins in the slotsl If it were me I'd do a thin fin fillet with epoxy, just to get the very smooth, tiny radii finish

 

[Micromeister]

Oh, and the CA I only use for when I fold the shock cord mounts on the Estes kits, since I dont want to wait hours for the elmers or wood glue to dry. [/B][/QUOTE]

Change those goofy trifold mounts to around the motor mount with kevlar or beading wire and you'll cleanup the inside of your tubes I haven't used those awful things since the early 80's LOL!!!!

 

[Pat Butler]

Micro-- you mentioned that the white and yellow WOOD glues shrink the same. But doesn't the regular non-wood white glue shrink less than the yellow wood glue? It always seems that way for me and I get less distortion of the body tube.

 

[Micromeister]

Actually white glues are used as "wood" glues, but that's a whole other subject They (white and yellow) have about the same shrink rate. you'll get nearly the same draw in on the body tubes with just about any glue in a confined area such as the space between centering rings in our motor mounts. The solvents or liquifiers and/or water in these materials have to go somewhere...if they can't vent they tend to draw in the cardboard fibers at the contact points causing what we're calling shrinking We can get the same reaction with ambriod, CA and some fast cure epoxies as well.
one way to reduce or eliminate this is to drill a small hole or 2 in the rear centering ring in a position that will NOT get filled with glue if it flows during drying. This will let the glue outgas without drawing in the tubing
Hope that helps

 

[Pat Butler]

That's interesting information. I didn't realize that it was more of a suction problem as compared to just the glue pulling itself in as it dries.

I'll have to try drilling a small hole or two, as that would be much easier to patch than the darn dents that usually end up in the tube. Thanks.

 

[Zack Lau]

I thought that Elmer's white glue is too soft to enable shrinkage to dent Estes paper body tubes.

 

[Micromeister]

Originally posted by Zack Lau
I thought that Elmer's white glue is too soft to enable shrinkage to dent Estes paper body tubes.

Soft???? Once dry, an elmer's white school glue "double glue joint" between tube and cardstock or wood is stronger the the material it is holding. likewise with yellow or brown carpenters glues.
Structurally i'd just as soon build everything with white glue.. yellows simply tack and set up a bit quicker.

 

[BobCox]

Originally posted by Vicious-Peanut
Oh, and the CA I only use for when I fold the shock cord mounts on the Estes kits, since I dont want to wait hours for the elmers or wood glue to dry.

How well have they been holding together for you? I was always told that CA should not be used near elastic because it attacks the rubber, in addition to being brittle.

 

[Motörhead]

Originally posted by BobCox
How well have they been holding together for you? I was always told that CA should not be used near elastic because it attacks the rubber, in addition to being brittle.

I've heard about that one too. On those rare occasions I use a tri-fold mount, I fold the mount in place with tacky glue and also use tacky glue to set the completed mount into the rocket. Once that's done, I brush a thin layer of 12-minute epoxy over the mount .... works like a charm. Other than that, I Quest-ify with kevlar/elastic whenever I can.

Interesting answers so far like I predicted, hats off to you guys.


Cheers ...... Pete

 

[teflonrocketry1]

I use white glue on the inside of the low power projects. The white glue doesn't grab on couplers and thick rings like yellow glue does. I use white glue on shock cord mounts that way if the rocket gets stuck in a tree the shock cord will loosen up after a few good rains and the rocket might fall to the ground. I also have replaced entire motor mounts that were glued in with white glue by carefully wetting and then unwinding the tubes and rings. I use the water proof yellow carpenters glue to affix fins and launch lugs to the outside of the rockets.

Bruce S. Levison, NAR #69055