Always Overdo it With the Glue

[brockrwood]

I tell myself before I start gluing: Put the glue on sparingly. Then when I start applying glue my subconscious says, “Slather it on! More! More! We don’t want anything coming off!”

Suggestions on how to fix this psychological problem?

 

[boomtube-mk2]

Buy more expensive glue.

OR, build a few N-Scale laser-cut structure kits.

 

[tsmith1315]

Try sneaking up on yourself from behind- Use epoxy because it's more expensive and you'll be more inclined to conserve.

I mix as little as one drop from each bottle.

 

[Bill S]

There is a fine line between too little and too much. Too little, and your fins break off upon landing (had this happen with my Estes Vesta Intruder), and too much and you introduce too much weight and drag.

 

[neil_w]

There is a fine line between too little and too much. Too little, and your fins break off upon landing (had this happen with my Estes Vesta Intruder), and too much and you introduce too much weight and drag.

To be fair, those Vesta Intruder fins are asking for trouble, by their nature.

Also, we should probably draw a distinction between fin fillets (where you're *not* trying to minimize glue) and glue used in other situations.

 

[samb]

I rather unimaginatively wrote myself a big Sharpie note and put it on the workbench:

CLEAN BUILD

Had it pinned up there for the longest time. My biggest issue is keeping my hands clean during a build session. I periodically review threads here from @SCIGS30 and Chris Michielssen's model rocket building blog for inspiration. Also, when I was a kid, my model airplane building uncle told me glue not in contact with the mating surfaces is wasted glue.

 

[Joekeyo]

I learned that using more glue prevents seizing when installing engine mounts. Otherwise, less is usually better.

 

[lakeroadster]

I tell myself before I start gluing: Put the glue on sparingly. Then when I start applying glue my subconscious says, “Slather it on! More! More! We don’t want anything coming off!”

Suggestions on how to fix this psychological problem?

If you're talking about wood glue... and you're not building a competition rocket... more is safer...

I'm Alfred E. Newman... and I am a glue-a-hollic

 

[bjphoenix]

I use Titebond II for LPR, mostly because I have it in my workshop already. "Too much" is hard to define. If you put a lot on then it is hard to hold it position while it dries, and it takes a long time to day, but most of the volume seems to go away. For fin fillets, even for relatively small fins, I have to put on about 3 layers to get what I think is a big enough fillet.

 

[neil_w]

I use Titebond II for LPR, mostly because I have it in my workshop already. "Too much" is hard to define. If you put a lot on then it is hard to hold it position while it dries, and it takes a long time to day, but most of the volume seems to go away. For fin fillets, even for relatively small fins, I have to put on about 3 layers to get what I think is a big enough fillet.

Titebond Quick and Thick is your friend for fillets.

 

[brockrwood]

There is a fine line between too little and too much. Too little, and your fins break off upon landing (had this happen with my Estes Vesta Intruder), and too much and you introduce too much weight and drag.

My biggest problem is just too much epoxy glue. Looks ugly when I use too much. I use it when I need to bond plastic to paper, cardboard, or wood.

 

[brockrwood]

Try sneaking up on yourself from behind- Use epoxy because it's more expensive and you'll be more inclined to conserve.

I mix as little as one drop from each bottle.

It’s the epoxy I overdo it with. Super strong but ugly when I use too much.
Like this:

 

[neil_w]

It’s the epoxy I overdo it with. Super strong but ugly when I use too much.

Solution: use less.

Motivate yourself by reminding yourself how heavy it is.

 

[brockrwood]

Solution: use less.

Motivate yourself by reminding yourself how heavy it is.

These fins are not coming off. But not an award winning look.

 

[tsmith1315]

It’s the epoxy I overdo it with.

30 minute?

 

[brockrwood]

30 minute?

5 minute. I think that is part of the problem. I was rushing to get the epoxy on with my chopstick before the epoxy dried in my plastic cup. I got frustrated with the dispensing tube thingy because it kept popping off. Went with the epoxy by chopstick method.

 

[bobbyg23]

Buy more expensive glue.

OR, build a few N-Scale laser-cut structure kits.

That is the truth. Start building N scale and you will learn quickly

 

[tsmith1315]

5 minute. I think that is part of the problem. I was rushing to get the epoxy on

Yeah, the quick cure can lead to rash decisions. I always mix small portions, typically nickel-sized batches for work on MPR/small HPR sized fins. Especially with quick cure.

My suggestion is to experiment with a bit of scrap. Cut a piece of scrap the size of a typical fin root you work with. Then mix the smallest amount you can mix and use that to attach one or two pieces. Let it cure and then see how much effort it takes to pull it apart.

 

[Hobie1dog]

Quit using cheap hobby glues and step up to the plate and use real professional epoxy Stuff that is used for high tensile strength products. The two part cartridges go in a pistol gun which allows you to squeeze out almost perfect fillets and properly mixed and the tips are very cheap so when you get done you throw the tip away and then use the cartridge Again by just simply putting a new tip on These are extremely high grade adhesives. Do a Google search for "Global Adhesives"
gep-110-50b is the 5-minute epoxy I use.

 

[samb]

Choose any glue you want. Technique will get you closer to fillet nirvana. There are actually quite a few threads on the subject here.
And then you can kill a few days looking through YouTube videos on the subject.
Most involve tools like masking tape, plastic spoons, sections of pvc pipe, gloved fingers, fondot balls, popsicle sticks, … and a little math to determine the optimum size based on the length of the fin root edge. Experiment, find your method/materials and enjoy the process.

 

[Donnager]

Quit using cheap hobby glues and step up to the plate and use real professional epoxy Stuff that is used for high tensile strength products. The two part cartridges go in a pistol gun which allows you to squeeze out almost perfect fillets and properly mixed and the tips are very cheap so when you get done you throw the tip away and then use the cartridge Again by just simply putting a new tip on These are extremely high grade adhesives. Do a Google search for "Global Adhesives"
gep-110-50b is the 5-minute epoxy I use.

I'd suggest looking at the Henkel line of epoxy adhesives. The Hysol (E20HP/others) stuff doesn't flow and it is very strong and not as brittle as Rocketpoxy.

It is a little pricey, but I find I don't oversize batches and I've had excellent luck with it.

 

[neil_w]

For gluing on LPR plastic fins to cardboard body tubes the brand of epoxy is not a relevant issue.

 

[David_Stack]

From your photo, it looks like you are attempting to both adhere the fin to the body tube, and shape a fillet in a single action. You may want to consider revising your technique to attach fins in a two-step process.

Apply a small bead/thin layer of epoxy to the root of the fin and attach it to the body tube. Allow that to cure, and then as a separate activity later go back and apply fillets to each fin. You may not even need to use epoxy for that fillet, since the bond of the plastic fin to the body tube using epoxy is already done.

Consider also masking off that portion of the body tube where adhesive will NOT be applied, and scuffing the exposed body tube to remove some of that shiny outer layer to improve the adhesion of the glue to the body tube. (scuff the root of the plastic fins as well if you are not already doing so)

 

[brockrwood]

It’s the epoxy I overdo it with. Super strong but ugly when I use too much.
Like this:

View attachment 495981

I know, I know. Ugly as heck. I will call it a practice rocket. Those fins are not coming off, however, so primary objective achieved.

 

[DES]

It’s the epoxy I overdo it with. Super strong but ugly when I use too much.
Like this:

View attachment 495981

I don't think this is too much epoxy, it just needs to be struck off and shaped better. l A popsicle stick or a finger tip, drag off about 2/3rds of the gel, and you have a nicely formed fillet.

But for these Estes rocket fins, put the glue on just the fin, not the tube. Enough glue to get just a little squeeze out is plenty. And then drag it off with a finger tip. You are wearing nitrile gloves, yes?

 

[Ronz Rocketz]

For gluing on LPR plastic fins to cardboard body tubes the brand of epoxy is not a relevant issue.

Agreed. I've come the realization that epoxy is overkill for LPR. Too heavy and the epoxy easily pulls off the cardboard. It's great for internal fin fillets. Q&T is my go to for fillet.

 

[Donnager]

Generally, when I do a lot of epoxying, I have gloves, a couple rolls of paper towels and some rags available. I also keep acetone to help completely wipe dribbles off. If you have that stuff within reach as you work, you can help the epoxy hygiene. I still seem to get it everywhere.

I probably get more on the towels when using hand mixed epoxy, than when I use a cartridge with a static mixer.

 

[brockrwood]

I don't think this is too much epoxy, it just needs to be struck off and shaped better. l A popsicle stick or a finger tip, drag off about 2/3rds of the gel, and you have a nicely formed fillet.

But for these Estes rocket fins, put the glue on just the fin, not the tube. Enough glue to get just a little squeeze out is plenty. And then drag it off with a finger tip. You are wearing nitrile gloves, yes?

Sadly, was just using a chopstick.

 

[GlenP]

When I was a kid I liked building plastic models and never quite got the hang of those plastic model cement tubes. I would usually get too much squeeze out and it would keep coming out, then it would spider web all over. When I would put parts together excess glue would squeeze out and get on my fingers and I would get my fingerprints melted into the model all over.

My older siblings would always comment, that is a nice model but you used too much glue. I didn’t know how to turn the glue off, you squeeze that metal tube and it just keeps coming out.

Later on I figured out how to put the glue in a paper cup and use a toothpick. And yank it quickly to break the spider webs. I could manage to get a drop right where I wanted it.

 

[neil_w]

Later on I figured out how to put the glue in a paper cup and use a toothpick.

I, on the other hand, learned that technique... let me think for a moment... ah yes: just now.