Estes plastic parts

[powderburner]

How do all of you guys assemble the Estes plastic parts (NCs, fin cans, etc) to the cardboard BT material so that it stays put?

I have been using Testor's plastic model cement (the kind in the little foil tube, like you use for assembly of non-flying styrene models). I think this is the recommended adhesive, and it looks like it does a good job when you first assemble a rocket, but after one or two flights the plastic pieces are coming loose from the cardboard BT.

I don't think this is a good place for CAs or epoxies, because they are usually kind of brittle. So what kinds of glues do you guys use?

 

[billeblurzz]

Powderburner, I gave up on Testors cement LONG ago! Even though recommended, it just does not bond to cardboard very well because plastic cement has to WELD two pieces of plastic together. I use different epoxies and some CA for different tasks. First you must ROUGH up the plastic piece and the cardboard tube with sandpaper. For RIGHT NOW sticking like plastic launch lugs, parts, etc., 5min epoxy will set up and hold the plastic part to the cardboard with some flexibility. For stronger bonds that will stay in place without actually HOLDING them together like plastic nose cones to body tubes, some plastic motor assemblies into body tubes, plastic couplers to body tubes, etc., 30min epoxy gives the STRONGEST attachment and acts as a lube for easy assembly. In fact, I use 30min epoxy for ALL my body tube to coupler joints because the LUBE effect helps from "grabbing" too soon. For plastic to plastic assemblies, use the LIQUID plastic cement applied with a small brush.

 

[DynaSoar]

Originally posted by powderburner
How do all of you guys assemble the Estes plastic parts (NCs, fin cans, etc) to the cardboard BT material so that it stays put?

I have been using Testor's plastic model cement (the kind in the little foil tube, like you use for assembly of non-flying styrene models). I think this is the recommended adhesive, and it looks like it does a good job when you first assemble a rocket, but after one or two flights the plastic pieces are coming loose from the cardboard BT.

I don't think this is a good place for CAs or epoxies, because they are usually kind of brittle. So what kinds of glues do you guys use?

I've built a few models out of styrene stock and body tubes as well as some plastic fin can birds. Plastic cement is fine as long as you make sure there's enough surface area for it to bond to. Fin root to body, you should add a flange to the fin first. I add a length of styrene L rail along both sides of the root first. Fin can to body, there's plenty of area, but the tube might need prepping. Always sand the tube first. Also, a series of pin holes in the tube where possible makes for a lot of little places for the glue to seep through and dry into little rivets. Works like a charm. Plastic doesn't need prepping, because what the glue does is melt the plastic. Along those lines, make sure you let the cement melt the plastic a bit before you stick the parts together. Putting a layer on both parts and waiting 30 to 60 seconds for the glue to soak into the paper and melt the surface of the plastic should help.

Plastic cement (the thick stuff in the tube) makes excellent fillets too. It flows like epoxy when wet, and you can tip the bird back and forth to get it to coat evenly on the fin and tube, it dries smooth, clear and concave, and doesn't tend to get bubbles that collapse and leave pits, like wood glue does.

 

[powderburner]

I have been gluing plastic models together for longer than I have been building rockets, and I know painfully well how the Testors-style cements chemically 'melt' the plastic. I usually do all the steps (light sanding of join surfaces, checking dry-fit, etc) that DynaSoar mentioned plus have experimented with extra steps like wicking thin CA into joints after the plastic cement has set.

What I suspect is really going on is that Testors has modified the formula of their cement and it just plain does not work as well as it used to. I know they changed their product some years back to reduce the volatiles, so that the snifferheads would not get such a buzz. I have also noticed that this glue does not seem to 'stick' and hold as well when working non-flying plastic models.

Sounds like the blurzz 30-min epoxy could be the way to go. I have stayed away from epoxies in this application, but maybe I need to experiment again? How many other guys use epoxy, or anything else?

And if we are all continuing to have problems with Testors glue, shouldn't Estes change their instructions and recommend something else?

 

[Stymye]

I use weldbond glue .
I built my honest john out of it exclusivly just to see how well it works .
good for bonding dissimular materials and dries crystal clear

 

[Habu]

I've had good success joining the plastic to paper tube using yellow carpenters glue after roughing up the sufaces to be joined.

 

[Silverleaf]

I use Great Planes Pro Wood Glue with Aliphatic resin. Bonds very well. One key I've found is make a few horizontal rough stripes on the area in question with some medium sandpaper - like this:

Base of plastic cone
________________

___________
___________
________
___________
___________

________________
end of glueable area

as it tends to help the resin grab and hold.

 

[davel]

For critical plastic to cardboard joints, consider Devcon 'Plastic Welder' (https://www.devcon.com/devconfamilyproduct.cfm?familyid=182.0&catid=37) or other MMA type adhesive.

 

[bobkrech]

Testors make several plastic cements. Only a few will bond plastic to cardboard or metal. One is specially made for model rockets. It's really important to read the label on the tube as pure solvent cements won't work.

This is the right Testors cement for rockets.

https://www.testors.com/catalog_item.asp?itemNbr=1471

Green is good.

All Testors cements.

https://www.testors.com/catalog_browse.asp?ictNbr=11

Really good finishing guide.

https://www.testors.com/hobbyist_guides.asp

Bob Krech

 

Lately I have been using Loctite brand Quicktite Super Glue Gel. The gel formula is the best as it does not run everywhere and you can apply just the amount you need, where you need it. It also dries quickly and is readily available at most hardware stores.

 

[Hospital_Rocket]

There is a CA based adhesive by Loctite called Black Max 380 that is toughened by adding a rubber filler rubber CA.

I used to use it in high vibration applications.

Might be worth a look.

A