Yellow Carpernter's Glue

I have read threads here about this stuff many times and it seems that it is all that some folks use. The particular brand I had was Weldbond and I decided to use it on the fin can/motor mount of an Applewhite saucer just to give it a go.
I tacked the fins and launch lug on with thick CA glue and let it harden, then filleted with the carpenter's glue. First of all, I am glad I was not in a hurry, as it took hours for each set of fillets to dry. When they did dry, it seemed that the glue was mostly liquid, because all that was left was a thin yellow skin. It will take at least two applications to get good fillets. To actually glue fins on with this stuff, I would have had to hold them in place for twenty or thirty minutes, minimum.
I will go back to gel epoxy for filets. I have never had one fail, it is set in 5 minutes, and one application is all that is necessary. I can mix enough for two sets of fins and rotate or hold the rocket in any position to work on it without having the stuff run everywhere. Smooth and wipe excess with alcohol, and it it is done.
I do and will continue to sometimes use yellow glue for certain construction projects, like motor mounts.

I used Elmer's yellow glue last night to attach the fins on my Estes Phoenix. My first time using it for fins. I've been using CA for fins, followed by Elmers to make the fillets. But, I'm not sure if I'm happy with the Elmer's for the fin attachment. It set up fairly quickly so I didn't have to hold it for more than a few minutes. But, as it dried I think it shrunk up and pulled my fins slightly out of alignment. I had them perfectly vertical (90 dgrees) But, after they dried the were no longer perfect. So, that bugs me a bit. I may go back to my previous method.

Regards,
Todd

rbeckey,

It must be technique and I like you don't have it. You'll find some only use water based glue and swear by it. I do, however, use water based glue on internal parts on low powered rockets.

I use 15 minute epoxy exclusively on all my rocket fin fillets. I've had better experience keeping fins on with epoxy. If a fin does break it is usually above the epoxy joint. For me repairing and refinishing a break above the fin fillet joint is easier. Reattaching then refinishing at a bodytube to fin attachment break is much harder for me.

oops, I pressed the reload button one to many times...



Regards,
Todd

Personally, I love yellow carpenter's glue for low power modrocs, but you're right about one thing - you can't be in a hurry. What I usually do is tack them on just at the root, get them all on at the root, then prop up the rocket so I can do two fillets at a time. I'll put on two fillets, go upstairs for a little bit (usually about 15 minutes), then rotate and do the next two. I've never had a problem with this method.

Loopy

Loopy,
We must be using different brands. The Weldbond was still liquid at the thirty minute mark. There was very little "build" in the fillets, just a skin coating on the first go around, requiring a second coat for a proper fillet shape. Ones I put a second coat on were not completely dry after four hours.
What brand do you use that is set enough to turn in fifteen minutes? That is not an unreasonable time in my opinion. Several hours is, at least for a model rocket.

I am not sure, but I don't think Weldbond is the same as yellow or carpenter's glue. I use Titebond or Probond.

Scott

I use Elmers yellow (carpenters) glue and it dries much faster than you describe. Maybe the brand makes a difference?

Keith

Here's a technique that works great for yellow glue joints.
Apply a thin smear of glue on the fin roots, and likewise on
the BT where the fin will be attached (I always sand off the
glossy finish first, this greatly increases the glue's holding
power).

Then, sit back and relax, or do something else, for about 10
minutes (maybe more or less depending on the temperature and
humidity), letting the glue dry a little until a 'skin' forms.

Then apply another fresh bead of glue onto the fin root, and
press firmly into place. The result is almost like contact cement;
it will 'grab' and hold the fin fast. Allow the joints to dry normally
and then apply fillets as you usually do. I've done lots of fins
this way, it makes life a lot easier and produces a mongo strong
bond, to boot.

Forgot to mention, I use Titebond when using water based glue. It dries fast and works terrific. No real good reason, I just like it.

The method described by vjp makes a good joint and using a small drill bit to make holes in the fin root and the body tube lends to even a stronger joint, kinda like rivets. I've used vjp's technique many times but still prefer, for my use, an epoxy joint.

I have been using Titebond for years with very good results. I use the method desribed above. I apply a small bit of glue to the root of the fin allow it to dry then glue it to the body.

It does stay liquid for a while, but in my opinion this is a good thing. It allows the glue to soak into the paper and wood and provide a good bond.

Once I have a good dried bond on all fins I tip the model sideways and run a fillet two at a time in the 'V' created by the fin/body tube area.

The trick to keeping it from shinking too much is not to apply so much glue. The more glue the more liquid that has to evaporate and thus more shrinkage.

It take some patience working with wood glue, I add some glue in the morning and when I come home from work and before going to bed.

I like it because it is cheap, none toxic and in many cases it has been shown to be stronger then CA and epoxy.

Scott

Originally posted by seo
I am not sure, but I don't think Weldbond is the same as yellow or carpenter's glue. I use Titebond or Probond.

Scott

Click to expand...

OK, I was wrong. Weldbond and Yellow glue are both polyvinyl acetates.

Been making fillets for many years. Don't like to take days to finish a four fin model rocket. Epoxy makes a smoother, quicker setting joint that is extremely strong. Never had a fillet crack before a fin when using epoxy. I will concede that there appears to be something amiss with the bottle of yellow glue I have. I will get another brand.

In my opinion West Sytem epoxy is the the best hands down as far as fillet adhesive (it's also good for gluing stuff in general). The problem is first you have to find someone who sells it then spend the money to buy the multiple things;resin, hardener, pumps, filler, and the multiple accessories if you want them. But if you get it, it is definitely worth the money. Plus the boat store people give you funny looks when you tell them what you want it for.

I have been using god ol' Elmer's white glue for over 45 years to build rockets.

For low power and most mid power models, Elmers gives me the best joints (usually the balsa breaks first or the tube comes apart.)

The best fillets, I use my fingers to shape it. (sometimes it take multiple applications but who cares!)

Lots of working time, (not looking for speed building here)

Easiest cleanup with just water...or let it dry on your fingers and peal off the fingerprints later.

ABSOLUTELY! NON-TOXIC!!! ya can't beat that in this day and age!

Makes a great sealant for fins and balsa nose cones! (mix some up with some talcum powder to fill balsa grain! Works Great!)

The only thing I think they have changed on the Elmer's formula in all those years is the smell...not as "sour milky" as it used to be...I kinda miss that!

No pumps, no rubber gloves, no repirators, no bio-hazard suits!

sandman

Originally posted by sandman
...Lots of working time, (not looking for speed building here)
...

Click to expand...

Exactly. I guess I'm one of those people who don't need, or want for that matter, to build and fly a rocket on the same day. Relax, enjoy the building process. It's half the fun of rocketry.

Sandman, I'd like to hear more about your white glue/talc balsa filler technique. Ratio of glue to talc? How sandable is it? How "clumpy" is it after mixing (meaning, how bad or how much sanding is needed?) How many coats for average balsa?

I'm intrigued..........

I use yellow glue (titebond II)
for fins I do a double glue joint so the fin doesn't need to be held more than a minute..or I use Cya to initially attach the fin

you can put too much on a fillet and takes forever to dry than it leaves dimples when it shrinks..the trick I found is to keep it thin
I don't like it on centering rings ..it can grab the ring before you get it into position..and it sucks in the body tube when it dries

I also use Weldbond alot ..it's complety different from yellow or white glue..It's very strong and can bond plastic to paper or balsa
It also dries crystal clear so it's perfect for applewhite saucers
you can make a Weldbond fillet and it will not run, even upside down
(they claim it's used on the space shuttle)

bad thing is it shrinks even more than yellow
and never completly hardens

on anything beyond most mid power stuff I use West system epoxy

I use thin CA to mount the fins then I use yellow glue for the fillets.
I've use epoxy when I'm in a hurry otherwise I do the couple layers of yellow routine because it does shrink.

Originally posted by aksarben10
It take some patience working with wood glue, I add some glue in the morning and when I come home from work and before going to bed.
I like it because it is cheap, none toxic and in many cases it has been shown to be stronger then CA and epoxy.
Scott

Click to expand...

I second this post. Aksarben10 made all the same points that I would (and did a fine job of the point about 'patience' )
I believe Sandman chips in with additional truths, especially about white glue.
I love white glue. It is indeed cheap (a few weeks ago it was dirt cheap when all the stores had their back-to-school specials). From my experience it works as well as the more expensive yellow glues, the official 'wood' glues, and the gorilla glues. No I have not done any stress/strain testing or any kind of quantitative measurements, just built lots of rockets and never had a bird die due to bad glue. Yeah, epoxy probably is stronger and makes some heck-for-stout fillets, but come on here, guys, we are only talking about cardboard and balsa wood. Sometimes I think some of you guys would be doing assembly with a welding rig if you could figure out how to do (over-do?) it.
White glue definitely has some bad habits. If I put it on too heavy it skins around the edges before the middle of the fillet dries, leaving a ridge around the edge, and often leaving air bubble holes in the middle of the fillet. So I don't put it on thick. And it probably does shrink some while drying, so you do have to be a little careful. White glue is not very easily sandable, so you have to be a little careful to apply it neatly.
On the other hand, you can water it down very easily to use for laminating paper onto balsa fins, penetrating glue into tight joints (like centering rings inside a BT), and making a light coating inside a BT for strength and flame-proofing.
Probably the best advantage is that if I can't find mine, I can steal from the kids.

Titebond II. Like has been said - sometimes takes two coats, but it's worth it for the ease of use (no masks, mixing, or gloves, and cleanup is a breeze), and saves alot of weight.

Loopy

Bob:
Just a word about our building materials. Most of us are flying cardboard tube and balsa/basswood..whatever fins. it's the bond between the cardboard and wood that hold the thing together. CA and most epoxies become brittle in a very short time. True glues, Elmors white glue.(organic in origin) and Yellow glues, as someone posted eariler are polyvinyl acetates, cure slower but are way more flexible.
The method Scott discribed is called " Double Glue jointing". This bond is stronger than both the paper and wood it is joining. I'm sure you've heard the term " the Speed of balsa" where the balsa fins or body tube fail under very high thrust. Please note it's not the "Speed of glue" cause it's not the glue that failed it's the wood or cardboard taring away. If you are going to do anything I'd suggest using the yellow glue (I like elmor's personally but I do a lot of cabinet building also) double glue joint than fillets of 5 minute epoxy will keep those fins and motor mounts in place til you loose the model. The trick with white and yellow glues is to make that first application thin, it will dry to the touch in about 5 miuntes or so, than apply a generous bead and stick the fin to the model body. By the time you are happy with the alignment of the fin it will be tac'ed enought to hold. I like to have my models held horzontally on a fixture. Another tick is to attach opposite fins. giving them a little more time before having to fight gravity.
Like sandman said... slow down and enjoy the building phase also.
Hope this helps a little.

I mostly use west systems epoxy nowadays. However as an experiment much of my bruiser-exp was done with superbond polyurethane glue from mcmaster-carr. It does take 24 hours to fully cure so it is not any faster than using epoxy, but it is less messy and strong as all heck. Since it does require moisture to work properly all I had to do was take a damp paper towel and give all the parts a quick once over before glueing up. It also tends to "foam" a bit so you do have to take that into account.

I have recently switched to Loctite Professional Wood Worx yellow glue. Bonds with 2 TONS of strength. That's the same as many 30 min epoxies...

Patrick

I will stick to CA and epoxy. Arguing that it is too strong or overbuilding is like arguing that a seatbelt and an airbag is overkill. I have never had a joint like that fail before the materials that were joined.
I just put a THIRD coat of glue on the fin fillets that I tried the yellow glue on. The last coat is from a brand new tube of Elmer's, and the fillet is still very thin. In the saucer I am certain that it will be sufficient, since the fins are glued on both edges, but I would be putting a forth coat on any other rocket. That is too much. Now we're talking about more than three days to fillet three low power fins and a launch lug. Enjoying the build is one thing, but that is rediculous in my opinion. If I had four projects going all the time, I guess it might work out better.
I am not sure why I would use four applications of yellow glue for a decent fin fillet when one application of epoxy will give just as good it not better results? Toxic? Smells bad? I don't eat the stuff or even touch it with bare skin. It certainly doesn't shrink enough to dimple a BT or give lumpy fillets. I guess we will agree to disagree on this one.

nice topic drift but back to the first post:

well, we've been using Elmers for quite a while with good results. look, the crayon rocket was built with Elmers and it has survived 10+ flights with E, F, but mostly G motors - and a ride with an H97. yes the dirty secret is out, we did the level 1 with yellow glue - gasp!!

others of our rockets have 50+ flights, all done with yellow glue.

if you are having trouble with drips and blobs not drying, you are putting too much on! definitely do the double gluing: just put a thin skin on, let it dry (30 minutes tops), put another thin skin on and stick the parts together. hold for 20 seconds. let it dry for an hour then do fillets.

remember white & yellow glue shrinks as it dries which will be to your advantage when doing fillets.


if a picture is worth a thousand words to you then let me recommend you get the CD from Apogee "how to build level 1 rockets". Tim shows exactly how much glue to use.

even better, he shows how to spray paint without getting drips and runs. it's quite simple but eluded me for 30 years. just go pst pst pst and not pssssssssst like I was doing. again, less is more.


epoxy is great stuff but unnecessary for low power and most mid power rockets.

I think, also, that some yellow glues are more equal than others. I was using elmers wood glue with good results, but i wasn't amazingly impressed. Whenever I thought I needed extra strength, I would use epoxy.

Then I got a bottle of 'Great Plains' wood glue. The stuff dries as hard as a rock. I haven't gone through a thorough test of all yellow glues, but if yellow glue isn't working, I would double check 1) the technique (if it is still wet after 1/2 hour you put on way too much, also use the double glue joint) 2) the brand. Proper technique will take care of 95% of your yellow glue problem, the brand will take care of the rest.

Another important issue to remember about using epoxy all the
time, is the fact that repeated exposure to it may trigger a severe
allergic reaction in many people. Once "triggered", this sensitivity
never goes away - you're doomed forever. Therefore, one may
want to use expoxy *only* where epoxy is really necessary, and
stay clear of it when other glues may work as well, or better.

Oh, one other thing - not all epoxies are alike; many cure brittle,
and are succeptible to cracking. Ideally, one wants a joint that
will have some 'give' to it. I have heard that the slow-cure
epoxies are actually worse than fast-cure epoxies in this regard,
so it's actually to your advantage to use the fast-curing stuff,
even if the advertised strength rating is better on the slow epoxy.

-Vince "my wife wonders where all her bathroom dixie cups
keep disappearing to" P.

Many times I fillet with four minute gel epoxy. It is quite flexible, compared to most other epoxies.