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Sep 22, 2009
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What is the stongest bond for plastic? I finished assembling the fins my Rubiconn with Testors plastic cement. and they just pull off so easy. The glue should be dry by now, which it is.
YAY! A glue thread!

Oh, wait...that's for RMR...LOL! ;)

Anyways, I would say use some 5 minute epoxy. A bit heavy, but you are assured some sort of bond.

Originally posted by stealdesk
What is the stongest bond for plastic? I finished assembling the fins my Rubiconn with Testors plastic cement. and they just pull off so easy. The glue should be dry by now, which it is.

Very odd. I know you've built a bunch of models so it's not newbie syndrome. Brainstorms:

Try glue. The thin liquid that just melts the plastic, not the solvent-with-plastic mixed.

Is it high-impact polystyrene rather than the common stuff used in plastic models? Might need something like epoxy. If not, very very odd. Maybe thin some cement with glue, paint some on, let it sit to work on the plastic a bit, put on another coat, and hold it with pressure at first.

If the instructions called for plastic cement, the only other thing I can think of is, Wash plastic before gluing. It can have oil on it.

And then there's always CyA.
if its LPR, its easy to stick to CA. light weight, really fast, and decently strong. i've heard that it gets extremely brittle with time, but i've never had any problems. epoxy is pretty heavy, really strong, but a LPR bird doesnt need it. its just overbuilding. superglue, crazy glue, ZAP CA, those are your best bets.
It did not realy bit into the plastic it almost peals off I have not seen this glue do this before.:confused: I think I will just scuff it and CA. Oh I went to see if the nozzels were the same and to no surprise it sure was.
i have that testors glue...its junk. doesnt work for beans. i put my estes eliminator together with it and the fin-can was way loose after a couple launches. epoxied it up and it was ready to go...unforunately it was lost. lol.
I've had good luck with Testors Plastic cements, but you have to use the correct one. It's important to read the fine print and follow the directions.

They sell "red", "blue", and "green" labeled plastic cements, and the formulations are slightly different. Not all stick to cardboard or all plastics.

The "green" labeled stuff should be used for rockets acording to Testors recommendations.

You can download their catalog at

They also have a good modeling guide on-line at

Bob Krech
creating the best bond depends entirely on the specific Type of "Plastic" being joined.
Acrlyic and styrenes. make up much of the hobby model material and a liquid solvent materal like Testers liquid cement is Ok, Best is Methylene Chloride or MC for short. MC will weld acrylics and styrene plastics forming a joint stronger than the base material. Testors solvent is a good bit less aggresive, but will generally do the job. Other plastics and polycarbonates do not bond with either material mentioned above.
It's not PVC, is it? PVC would be a little odd for fins, maybe, but I think I've heard of it. You'd pretty much need an all PVC rocket or a mechanical bond (screws, etc.) somewhere along the way to make PVC work, since about all that will stick to it is PVC cement, and PVC cement sticks to almost nothing else well.
The Rubicon fins and most of estes fins do not like "hot "glues(cya, epoxy) so make sure its a good fit by sanding and just use small amounts.
on something like the Rubicon I have used Weldbond. It will bond anything to plastic(including plastic)

I subjected an -all weldbond- test model to a few G motors and not a sign of stress so far .
I'm suprised ,not a lot of stores stock it , I get it from a local "Freds"