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Arley Davis
04-24-2008, 05:04 PM
I have a problem with the China made Plastic kits from Estes, and I was wondering if others have had the same problem. Unlike many of you I do not mind the easier to build Plastic kits for a change from the more complicated time consuming kits. Also if my Grandson brakes the rocket or I loss it no big loss, just buy another and build it in an hour.
But back to the problem I have been having, the plastic Testes cement dose not work on the newer kits, it simply is not melting the plastic together.
Last year Jacob got the Lucky Seven for his Birthday, after building it and after its first flight the Nose Cone thatís in 3 pieces fell apart, upon inspection the nose cone joints were not melted and the glue could be scraped off. This year I purchased the Liquidator and last month I took it to our low power launch, and even thou I did not fly it because it was to windy, but still 2 of the fins came off from just setting on the ground.
Iím positive theyíre using the wrong plastic, Plastic Cement only melts certain plastics, and will not melt just any plastic. What do the rest of you thank?

Skippy
04-24-2008, 05:42 PM
The plastic used in some of the newer Estes kits will not 'weld' together with normal plastic model cement. I just use thin CA instead.

K.M.Knox
04-24-2008, 05:50 PM
One thing I have noticed that helps a little is to sand the joints being glued. It roughens up the conntection spots plus gets rid of the glossy coating that a lot of plastic parts seem to have. Even then, I also lean towards using CA on my plastic stuff.

One on my workbench is the Thunderstar, a lot of plastic in the kit. I sanded the nose cone, tower assembly, etc. and used regular Duco Plastic Modeler Cement. The whole nose assembly appears real solid for not using any CA on it, but only time will tell I guess. I do know I could not get any of the display nozzles with the X-Prize kits to stick on unless I sanded a little and used CA...

CPMcGraw
04-24-2008, 06:00 PM
I have a problem with the China made Plastic kits...the plastic Testes cement dose not work on the newer kits, it simply is not melting the plastic together...Iím positive theyíre using the wrong plastic, Plastic Cement only melts certain plastics, and will not melt just any plastic. What do the rest of you thank?

It probably is a difference in the plastic. Have you tried the orange-label Plastruct? I've used it with better success than the Testors for some applications.

Another that I've heard successfully used for Estes plastic components is Tenax-7R. This is another chemical solvent-fuse-weld type of cement.

As always, YMMV...

moonzero2
04-24-2008, 08:32 PM
This isn't a new problem. I've had it with the 2nd release Orbital Transport plastic nose cone. Also had this problem with the Comanche 3 nose cone too. I resolved it by ordering replacement balsa nose cones from BMS.

gpoehlein
04-25-2008, 06:57 AM
Which type of Testors plastic cement are you using? I've found that the tube stuff is near-useless. I've not had any trouble gluing the Estes plastic nose cones together (not tried on the X-prize kits) with Testor's liquid cement. The new bottle is pretty nice with the metal tube applicator.

Greg

ghrocketman
04-25-2008, 08:32 AM
The tube-type (orange tube, the blue tube is TOTALLY useless) Testors cement has changed formulas from what it was up until about 10 years ago. It now contains far less toluene and I'm pretty sure it no longer contains Oil of Mustard (Allyl Isothiocyanate).
Neither of these changes made the product better, they made it far worse for actually welding plastic together....I had heard that this was done to make the product less "sniffable" for the idiots who sniff glue....what a great plan....lower the quality of a product to near uselessness for the intended purpose in attempt to make it safer for numbskulls that belong on the "Darwin List" who use the product for some un-intended purpose.

The good news is that one can make Testors tube-type plastic cement nearly into the old formulation by squeezing the tube out into a 1oz glass airbrush jar or other similar bottle and mixing in some Toluene at 20-25% by volume with the contents of a 5/8oz tube of cement. One has to apply the glue with a brush, but it is a solution to those that cannot easily get their hands on Tenax 7-R or Plastruct or Ambroid ProWeld.

I personally just use Tenax 7R as the product works far better and faster than any tube-type Plastic Cement EVER has...with Tenax the joints are truly welded & I have yet had one break in over 20 years of use. The fumes from Tenax 7R, Plastruct, or ProWeld are far more irritating than Testors cement, but I find that a VERY SMALL price to pay for a far superior product.

Don't even bother with Testors Liquid Plastic Cement....the stuff is horrible for cementing most plastics....it isnow just a jar of MEK (Methyl Ethyl Ketone) which is good for cementing very few plastics and is best at NONE. Testors Liquid Plastic Cement used to be Methyl ISO-BUTYL Ketone, which was actually half-decent at cementing plastic, but nowhere near as good or fast as Tenax.
Why manufacturers change a product that works for a far worse product I'll never know...makes no sense to me and never will at any price-point of any goods.
I'd always rather spend more $$$ for a product that works well than a supposed "new & downgraded" replacement at the old price as I VALUE the dollars I spend and want them to go toward decently working products.

As a side note, never use Testors Green or Yellow tube cements for building anything that has to do with rockets in any way, shape, or form. These are wood cements that are suitable ONLY for constructing light tissue-covered rubber-powered free-flight model airplanes and they WILL fail when subjected to any sort of high-speed or high-load flight application. I have seen several people try to build rockets withe these glues in the past and they almost always result in spectacular flight FAILURES.

Royatl
04-25-2008, 09:11 AM
Iím positive theyíre using the wrong plastic, Plastic Cement only melts certain plastics, and will not melt just any plastic. What do the rest of you thank?

Yes Arley, I mentioned this almost three years ago when the various X-Prize rockets came out.

It is definitely the plastic formulation. I eventually built my Lucky Seven with ZAP for Plastics (a plastics forumulated CA glue). Same with my Thunderstar, but the escape motor nozzles could not be done properly, so I left them off. I still haven't built my Rubicons, but others have resorted to CA and epoxy, or even to mechanical means to attach the fins (and keep them attached!).

The good news is that the problem appears to be somewhat fixed in later products (Interceptor, D-Region Tomahawk), though I would still not recommend Testors tube glue, but either Tenax or Ambroid Pro-Weld, or one of the Plastruct glues.

ghrocketman
04-25-2008, 09:43 AM
I used Tenax on the wingpod and all other plastic-to-plastic joints on my Interceptor.
For mounting the wing pods to the balsa fins and the tailcone to the body tube I used 5-minute Epoxy.
NOTHING bonds plastic to unlike materials even close to nearly as well as Epoxy.
You do not need (NO 1/4" radius epoxy fillets for LPR, please) to use a lot to do this, so the weight penalty is NEGLIGIBLE.
Plastic CA will work, but the bond is not nearly as strong. Never try using plastic cement to bond plastics to non-plastic materials unless you like failed glue joints which WILL eventually happen.

Arley Davis
04-25-2008, 06:00 PM
Yes I to have used CA to glue plastic together, as for the other products mentioned I will check with Hobby Town and see what they have.
As for gluing plastic to other materials, I have found that CA is the best, Many years ago I built the Estes Saturn V using CA to glue the plastic parts to the rocket and no problem. Epoxy dose not adhere will to Plastic, G10 or Fiberglas fins and Nose Cones.

roguepink2
05-05-2008, 06:13 PM
Some tricks from the Estes model shop:

Tenax 7-R is great for most types of plastic, including the stuff Estes uses. Do not bother with Testor's stuff in the orange tube, its useless. If you want more control, I use BSI brand CA glues (Zap will do just as well) for most plastic jobs. You will have great results using a THICK CA glue for any plastic to paper joints. I also use the thick CA for fast balsa to tube joints and then will fillet with a bead of thick CA. Trust me, this is a FAST way to build a rocket, but even better, this is a great field repair method. Use some CA accelerator and you can be flying again in less than 10 minutes. Thick CA is also great for balsa to balsa repairs.

I stress, THICK CA glue, not the thin. The thick CA will fill any gap and create a solid bond where the thin will get absorbed into the paper or balsa and not make any bond at all.

2-part epoxy is great stuff, but a pain to sand, especially over balsa. The balsa surrounding the epoxy joint will be soft, the joint will be hard epoxy, and you will get uneven spots around it. Good for making solid joints, but not as nice for finishing.

mrhemi1971
10-14-2008, 07:47 PM
I had the same problem with my Rubicon. I spent the time to paint it and detail it, and couldnt keep a fin on the thing, tried sanding the plastic to rough it up beforehand, used ALL types of glues (Been building models professionally for over 30 years) and no matter what the fins would pop off at landing. The new plastic estes is getting I hate to say it, but it's JUNK!! I got so frustrated with the kit that I threw it away... I was hoping to buy a few more to make some neat Saturn 1B style boosters, but I wont waste my money till they can come up with a better quality of plastic. (and for me to say that is heartbreaking) I really used to enjoy seeing what was new with estes kits, but now I question the quality....PLEASE Estes...FIX THIS!!

Royatl
10-14-2008, 11:16 PM
I had the same problem with my Rubicon. I spent the time to paint it and detail it, and couldnt keep a fin on the thing, tried sanding the plastic to rough it up beforehand, used ALL types of glues (Been building models professionally for over 30 years) and no matter what the fins would pop off at landing. The new plastic estes is getting I hate to say it, but it's JUNK!! I got so frustrated with the kit that I threw it away... I was hoping to buy a few more to make some neat Saturn 1B style boosters, but I wont waste my money till they can come up with a better quality of plastic. (and for me to say that is heartbreaking) I really used to enjoy seeing what was new with estes kits, but now I question the quality....PLEASE Estes...FIX THIS!!


They seem to have fixed it with the more recent Interceptor(and -E) and D-Region kits. They obviously can't do it for the X-Prize kits as they have probably made all the parts for them that they're ever going to make. Tenax or equivalent, or Zap for Plastics are probably the best you can do. I've seen some get away with epoxy on the Rubicon. Sooner or later, though, a fin's gonna pop.

jetlag
10-15-2008, 04:43 AM
Epoxy dose not adhere will to Plastic, G10 or Fiberglas fins and Nose Cones.

I'm sorry, but this is an incorrect statement. G10 and fiberglass are made with epoxy. As for plastics, as long as the mold release is cleaned off the part, and the part has good surface area with which to work, epoxy will work nearly every time.
Allen

barone
10-15-2008, 07:07 AM
WHere is one to find Tenax 7-R?

Bluegrass Rocket
10-15-2008, 07:51 AM
If you can't find it at your local actual Hobby Shop, try Ebay. I just searched Tenax and if you scroll down to buy-it-nows there are 2 listings for the Tenax 7R plastic liquid glue. The second listing shows a small picture and is $3.50 plus $3.50 shipping. I just tried some for the first time and it did indeed work great. I know Ebay can be a pain but, sometimes it is easy to find some things. Hope this helps.

barone
10-15-2008, 10:53 AM
If you can't find it at your local actual Hobby Shop, try Ebay. I just searched Tenax and if you scroll down to buy-it-nows there are 2 listings for the Tenax 7R plastic liquid glue. The second listing shows a small picture and is $3.50 plus $3.50 shipping. I just tried some for the first time and it did indeed work great. I know Ebay can be a pain but, sometimes it is easy to find some things. Hope this helps.
Thanks Rick. I'm going to check Hobby Lobby and Michael's. If they don't have it, I'll check with the local Hobbytown USA.

tbzep
10-15-2008, 11:52 AM
How long will Tenax last? I almost never finish a bottle of thick CA before it crystallizes. Heck, I almost never get half way through a bottle of it. Yes, I've refrigerated, sealed in zip-locks, etc.

Gus
10-15-2008, 01:14 PM
How long will Tenax last? I almost never finish a bottle of thick CA before it crystallizes. Heck, I almost never get half way through a bottle of it. Yes, I've refrigerated, sealed in zip-locks, etc.
Tenax is not a CA. I have a bottle several years old and it is still liquid. Just have to be careful to not leave the top off as it evaporates quickly.

Mr preferred cement of this type for plastic to plastic joints is Ambroid Pro-Weld. I love the way you apply this stuff, and Tenax. Unlike other glues where you apply the glue to the edge of one part and then put the other part on, with Pro-Weld you hold the pieces together, then use a small brush to apply a drop of the stuff to an inside seam line. It wicks its way in and holds the pieces together. Only downside is that it melts the inside seam line just a tad, so this is not a technique you want to use on visible surfaces (like a Mercury Redstone tower, grrrrrr).

As for thick CA, I've become a huge fan of the stuff for balsa to paper joints. But I no longer buy big bottles, it always hardens before I can use it all. Home Depot now carries 12 packs of the little tubes for ~ $6, which is what I use.

tbzep
10-15-2008, 03:44 PM
Tenax is not a CA.

I understood that it isn't CA. :)


But I no longer buy big bottles, it always hardens before I can use it all. Home Depot now carries 12 packs of the little tubes for ~ $6, which is what I use.

That's why I asked about the shelf life of opened Tenax. I never finish even the smallest bottle of thick CA before it hardens because I don't use much of it. I can usually finish off a bottle of thin because I use it to wick into balsa, body tubes, etc. to strengthen in addition to regular gluing purposes.

When I was building R/C planes, I went through thin pretty quick. I still didn't use much thick because I tried to fit parts close enough not to need its gap filling properties.

Rustee
10-16-2008, 02:15 AM
I did find the regular Testors cement very weak,the fins of my Rubicon would easily come off so I used Plasti-zap instead. I lost one fin on landing but it didn't break anything and I simply glued it back on. On another note,I used thick CA for the fins of my Rawhide(Semroc),put a C6-5 in it and the heat melted the glue! Once cooled it was perfectly solid again. Good prep work helps whatever you use though.

Mark II
10-17-2008, 12:19 PM
I understood that it isn't CA. :)



That's why I asked about the shelf life of opened Tenax. I never finish even the smallest bottle of thick CA before it hardens because I don't use much of it. I can usually finish off a bottle of thin because I use it to wick into balsa, body tubes, etc. to strengthen in addition to regular gluing purposes.

When I was building R/C planes, I went through thin pretty quick. I still didn't use much thick because I tried to fit parts close enough not to need its gap filling properties.
Tenax-7R has a consistency very similar to plain water. I don't know what is in the formulation, but does evaporate very quickly when I apply it to the bond seam, and it leaves almost no visible bead. All of the liquid (you use tiny amounts of it) just evaporates away at the joint, leaving the joint solidly bonded. It is sold in small glass jars, and I have had a jar of it for about a year. Granted, I don't use it very often, but in that year, I haven't noticed any decrease in the volume of liquid in the jar. So I would say that as long as you keep it tightly capped when you aren't using it, a bottle of Tenax-7R should stay good for a long time.

I had wonderful results using Tenax-7R when I built a small tower out of small, thin pieces of molded styrene. The key issue with it is that the pieces being bonded together must fit exactly together, with absolutely no gaps. It goes without saying that any bonding agent (I'm not even sure you could really call it a glue) that is as thin and volatile as this one will not bridge or fill even very tiny gaps or voids. The other thing is that unlike water thin CA, which bonds almost instantly, Tenax-7R takes up to about 20 seconds to form a bond. You have to hold the pieces firmly together for at least that long. If the pieces shift or separate even a miniscule amount, you will not get a bond. The stuff works great when you are bonding a lap joint, and the overlapping parts can be easily held together during bonding, as well as in joints where one part fits snugly inside the other, and also in butt joints that are pinned tightly together or which have alignment pins all along the seam (the fluid flows in and joins pin to hole as well as joining edge to edge). I apply it to the joint or seam with a Number 0 paintbrush; you don't need to use very much of it.

Where it does not work so well is in joining one piece to another with a simple butt joint (without internal pins), especially if the pieces are on the large side (I'm not sure of the limit, but let's say, 2" or more) and especially if they are joined at an angle. You might be able to get away with using it to make a 90 degree angle shaped beam out of two strips of 0.125" wide styrene, for example (as long as you held both pieces absolutely still), but if you try to butt-join two 4" x 4" sheets of 0.020" thick styrene together at a 30 degree angle using Tenax, it will not hold. (Trust me, I've tried it.)

BTW, I have seen other formulations of Tenax, too (Tenax-XY, or Tenax -[number][letter]) but I don't know what they are used for.

Mark \\.

tbzep
10-17-2008, 04:00 PM
Thanks. We should have a glue/bonder FAQ and this should be in it. :cool:

I think I'm going to pick up some somewhere. My son's Interceptor pods came apart when he was sanding on it the other night. He used Testor's tube type. This sounds like it would work well for the pods. I might also hunt up some ProWeld that was mentioned earlier and try it.

Commonwealth.net
10-21-2008, 10:22 AM
Most current "airplane" glue no longer has MEK.
MEK is the chemical that "welds" the parts together!

It is nor longer used so kids wont sniff the glue and get high.

To glue plastic either use "super glue" of Devcon Welder.
The Devcon product is sold @ Commonwealth Displays.
http://www.commonwealth.net

Mark II
10-22-2008, 12:30 AM
Most current "airplane" glue no longer has MEK.
MEK is the chemical that "welds" the parts together!

It is nor longer used so kids wont sniff the glue and get high.

To glue plastic either use "super glue" of Devcon Welder.
The Devcon product is sold @ Commonwealth Displays.
http://www.commonwealth.net
You mean that big can of MEK that I can buy in my local hardware store is nothing but a lifetime supply of plastic cement???

:chuckle: :D :chuckle: :D :chuckle:

Mark \\.

tbzep
10-22-2008, 07:27 AM
You mean that big can of MEK that I can buy in my local hardware store is nothing but a lifetime supply of plastic cement???

:chuckle: :D :chuckle: :D :chuckle:

Mark \\.

IIRC, you can dissolve some styrene in the MEK to thicken it and it should end up much like the old fashioned tube type cement that actually worked.