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Cl(VII)

Cl(VII)

Chris Bender, Lab Rat
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I have a D-Region Tomahawk and an Estes Nike Smoke in the build pile, both require some plastic-plastic and plastic-carboard glueing. Model glue is not so good, so what specific adhesives have you had good luck with on plastics?

Thanks in advance
Chris
 
Cl(VII) said:
I have a D-Region Tomahawk and an Estes Nike Smoke in the build pile, both require some plastic-plastic and plastic-carboard glueing. Model glue is not so good, so what specific adhesives have you had good luck with on plastics?

Thanks in advance
Chris
Click to expand...

I wonder what posts you've been reading...
 
K'Tesh said:
I wonder what posts you've been reading...
Click to expand...

Indeed, this was brought about by your D-Region Tomahawk post. I was trying to get a more general discussion on the subject of plastic adhesives going. Bonding plastic appears to be a far more dark art than paper, cardboard, wood, and composites even. "Plastic" is probably even too general a term as there are so many differnt plastics, each with their own properties, so I was hopeing to drag some of the modelers into the discussion. It appears to not be working at this point. Oh well, I'm going to leave work a bit early and pick the brains over at the local hobby shop, but I figured I'd try here first.

I love building rockets, but I HATE repairing them. This is probably why I have 16 different adhesives in my "glue carrier". Every combination of materials has a best adhesive, and that's what I'm trying to determine.
 
Cl(VII) said:
what specific adhesives have you had good luck with on plastics?
Chris
Click to expand...
For the D-Region, the simplest solution is to just use 5-minute epoxy for anything involving plastic.

If you can find Tenax-7R or Micromark "Same Stuff" that works well for plastic-plastic (polysterene).

Bonding milk-bottle plastic (high-density polyethylene) is very difficult. If you have to, use epoxy, scuff up the plastic, use some other form of mechanical support where possible, and hope for the best.
 
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Cl(VII) said:
Indeed, this was brought about by your D-Region Tomahawk post. I was trying to get a more general discussion on the subject of plastic adhesives going. Bonding plastic appears to be a far more dark art than paper, cardboard, wood, and composites even. "Plastic" is probably even too general a term as there are so many differnt plastics, each with their own properties, so I was hopeing to drag some of the modelers into the discussion. It appears to not be working at this point. Oh well, I'm going to leave work a bit early and pick the brains over at the local hobby shop, but I figured I'd try here first.
Click to expand...
Given the approximately 8,677 D-Region Tomahawks people have reported buying in the past 48 hours, there should be quite a demand for this information.
 
Cl(VII) said:
Indeed, this was brought about by your D-Region Tomahawk post. I was trying to get a more general discussion on the subject of plastic adhesives going. Bonding plastic appears to be a far more dark art than paper, cardboard, wood, and composites even. "Plastic" is probably even too general a term as there are so many differnt plastics, each with their own properties, so I was hopeing to drag some of the modelers into the discussion. It appears to not be working at this point. Oh well, I'm going to leave work a bit early and pick the brains over at the local hobby shop, but I figured I'd try here first.

I love building rockets, but I HATE repairing them. This is probably why I have 16 different adhesives in my "glue carrier". Every combination of materials has a best adhesive, and that's what I'm trying to determine.
Click to expand...

I completely agree with what you said...

If Estes keeps the Tomahawk in production, I hope they come up with better instructions for the plastic on cardboard/plastic on plastic adhesives.

Reading the replies in my thread makes me really worried that someone's going to have an accident because of a bonding failure between materials.

And I think Rich is right. This is going to be very important to a lot of builders in a very short time.
 
mikec said:
For the D-Region, the simplest solution is to just use 5-minute epoxy for anything involving plastic.

If you can find Tenax-7R or Micromark "Same Stuff" that works well for plastic-plastic (polysterene).

Bonding milk-bottle plastic (high-density polyethylene) is very difficult. If you have to, use epoxy, scuff up the plastic, use some other form of mechanical support where possible, and hope for the best.
Click to expand...
eRockets has Tenax 7r (says Amazon) but it'll cost you $10 for an ounce, delivered, and they only have 10.

Couple threads from a model train forum I found on Google (and with no toilet paper ads!)

https://www.trainboard.com/grapevine/showthread.php?147733-Is-Tenax-7R-officially-gone
https://www.trainboard.com/grapevine/showthread.php?151065-Tenax-7rTamiya liquid cement

Alternatives listed there include Tamiya liquid cement, Ambroid ProWeld, Plastruct Bondene (white label), Plastruct Plastic Weld (orange label), MEK either straight or with toluol added, and "plain old lacquer thinner" which is said to be (wait for it) MEK with toluol added.
 
K'Tesh said:
Reading the replies in my thread makes me really worried that someone's going to have an accident because of a bonding failure between materials.
Click to expand...
I think you're overstating this risk a bit. At any rate, see my response above -- just use epoxy and you'll be fine.
 
mikec said:
I think you're overstating this risk a bit. At any rate, see my response above -- just use epoxy and you'll be fine.
Click to expand...

I plan on using epoxy... but not everybody who will be building this kit (or others like it) may know not to use the tube-type plastic cement. They might not think to look here for the info on better bonding methods.

If a fin falls off, or a LL goes missing, you've got a problem. Likewise, not everybody will be launching in an area that is completely fireproof. My school launches as a highschooler were done on our playing field, right up against the field of crops that bordered the school. We never started a fire, but it could have happened if a rocket went unstable and fell into the wheat.

If I had the resources, I'd like to build one with one fin/LL attached per the instructions, and the remaining fins and LL with improved adhesives, and see how strong it really is/can be. I mean, I'd test to destruction (with out launching).
 
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K'Tesh said:
If a fin falls off, or a LL goes missing, you've got a problem.
Click to expand...
I built a D-region following the instructions with plastic cement and flew it many times in that condition. The fins tended to pop off on landing but I didn't have any fall off during flight. I agree that if the instructions were to be rewritten, they should just suggest using epoxy. The kit is many years old and will soon be OOP as far as I can tell, though.
 
However, the instructions could be updated (online), and Estes could fix other similar mixed-materials-using kits that they have in production, or are planning on putting into production.
 
Cl(VII) said:
... so what specific adhesives have you had good luck with on plastics?
Click to expand...

I've had really good luck with epoxies specifically formulated for plastic. They did a fine job bonding to paper, too. You can find these specialty epoxies at Home Depot, Lowes, et cetera. This didn't prove a panacea, however, because these products have a practically non-existent shelf life (once you open the packaging).

I also have a glue "arsenal" with over a dozen different kinds. I experiment to see what gives a good bond, without roughing things up. However, buying all these glues does cost money.

Another alternative is to make some mechanical changes to improve strength. For example, drill holes through the plastic fin can, and into the paper tube, then insert plastic dowels... stuff like that. I think, this type of minor innovation would also make the build threads more interesting.

Of course, you need to "watch" your CG.
 
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Chris, Tenax7 is the most often prescribed plastic-melting glue :)
however, since it's availability is sometimes hit and miss, I use Tamiya's equivalent - "extra thin cement". Testor's equivalent works well also.

the real trick to these are:

1.if any gets on desired surfaces, don't touch it. gonna happen though. sand it out

2. a capillary applicator is the best tool to apply the glue. see: https://www.micromark.com/TOUCH-N-FLOW-APPLICATOR,7841.html

3. the brush applicator in Tamiya's bottle is usable.

4. it dries/evaporates pretty fast, and it works by capillary action between the joined parts.

5. in practice, allow the joined parts and applied glue to.... how to say this... you might only apply it over a 1 inch length of seam, or a bit more or a bit less. In practice it depends on how well the seams go together with light finger pressure applied.

6. you could pick up an inexpensive plastic model -something- to practice on.
 
I should comment, that I used the Tamiya cement only to glue the fin-halves together.

I forget what I used to attach the fins to the rocket. probably thick CA. maybe epoxy too...cant recall.
Did not put on a epoxy fillet. should not need it.

OTOH, I have pretty much decided to static-display my model for now...
 
Estes and other manufactures kits are generally GPPS General Purpose PolyStyrene. Bonding it to itself or other styrene is called " Solvent Welding". several of the above mentioned "Hobby shop" available are fine for Plastic model building but are on the weaker side of the solvent range for High Stress Bonding needed for rocket or flying models. Tenax7, Plasticstruct or Ambroid "Pro-weld" are water thin solvents that work well by capillary action or applied with a fine hair brush. Testors water thin plastic cement is far to weak for our use but is fine for static plastic model construction. Better are meterials like Weld-on 3,4 & 16 for most Styrene, Acrylic and Polycarbonates, Best is MC. but is very difficult to find outside the sign supply industry in gal cans. Two Lowe's or Home depot available Chemical that will do a decent job are MEK and Acetone, these however must be used with care as they will completely desolve Styrene if applied too heavily.
If you'll visit www.narhams.org in the library section you'll find Tech-Tip-017 titled Working with Plastics. this is an in-depth look as working with many types of plastics and the best methods for joining similar and dissimilar substrates including plastics to cardboard or wood.
 
Thanks very much to those who have contibuted thus far. A lot of really good experience in there. I stopped off at the LHS on the way home and picked up a bottle of Tenax7, and I have some of the plastic epoxy left over from a BaddAzz build. Glad also to hear that there are products a step up from these should I ever have need. So I think I will be good for the current projects with the advice given here. Any more information/experience others have had is still very much welcome, and would be appreciated. I hope to be able to refer back to this thread in the future as a one stop plastics bonding thread.

Thanks again,
Chris
 
All I have ever used is HobbyLobby brand medium vis. CA on my Estes Tomahawk, Super Nova Payloader, Blue Ninja, all plastic to plastic fin attachments, never had a fin pop off. On my Super Nova Payloader snapped a fin in half after landing on a rock, root edge was still attached. Guess I'd rather have the fin pop off. I always sand the joining surfaces first though.
 
My Tomahawk, which I did not build, used 100% Bob Smith CA. Only thing that has broken was the thrust ring came loose on a hard landing -- cardboard to cardboard, way up in a tube.
 
I now have a bottle of Tenax-7R in my collection of adhesives. Picked it up tonight.
 
My son was building his first rocket a couple years ago, an Estes Outlaw, which required gluing the plastic fin section into the back of the cardboard body tube. The instructions specifically said to use plastic cement. I thought, hmmm, but Estes knows best.

First we tried using the Testors solvent based plastic adhesive. It fell apart before the rocket was even completed. We then tried the Testors tube type plastic glue which seemed to work... however. When we launched the rocket, the ejection charge popped the parachute out the top, but the fin can popped out the back. We were able to recover the fin section, but the nose cone / air frame thermalled away on the 12" parachute. Many tears ensued.

Lesson learned, +1 on the 5 minute epoxy for plastic/cardboard joints.
 
Micromeister said:
Estes and other manufactures kits are generally GPPS General Purpose PolyStyrene. Bonding it to itself or other styrene is called " Solvent Welding". several of the above mentioned "Hobby shop" available are fine for Plastic model building but are on the weaker side of the solvent range for High Stress Bonding needed for rocket or flying models. Tenax7, Plasticstruct or Ambroid "Pro-weld" are water thin solvents that work well by capillary action or applied with a fine hair brush. Testors water thin plastic cement is far to weak for our use but is fine for static plastic model construction. Better are meterials like Weld-on 3,4 & 16 for most Styrene, Acrylic and Polycarbonates, Best is MC. but is very difficult to find outside the sign supply industry in gal cans. Two Lowe's or Home depot available Chemical that will do a decent job are MEK and Acetone, these however must be used with care as they will completely desolve Styrene if applied too heavily.
If you'll visit www.narhams.org in the library section you'll find Tech-Tip-017 titled Working with Plastics. this is an in-depth look as working with many types of plastics and the best methods for joining similar and dissimilar substrates including plastics to cardboard or wood.
Click to expand...

I concur. I'm building mine using Pro-Weld (main ingredient is methylene chloride = nasty stuff that works) to weld the plastic parts together. For the paper to plastic joints I use a medium viscosity super glue. The usual aliphatic resin (Titebond) is used for paper to paper joints.
 
JMZawodny said:
I concur. I'm building mine using Pro-Weld (main ingredient is methylene chloride = nasty stuff that works) to weld the plastic parts together. For the paper to plastic joints I use a medium viscosity super glue. The usual aliphatic resin (Titebond) is used for paper to paper joints.
Click to expand...

Ok, now I feel like a freakin idiot. I pulled up the MSDS for Tanex7, and it is basically methylene chloride. I literally have 40 L of that at work. I just payed $5 for something I have tons of. :facepalm:

At least I know that my supply will never run out.
 
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XrayLizard said:
2. a capillary applicator is the best tool to apply the glue. see: https://www.micromark.com/TOUCH-N-FLOW-APPLICATOR,7841.html

....

6. you could pick up an inexpensive plastic model -something- to practice on.
Click to expand...

Thanks very much for this advice. I picked up one of those capilary applicators today at HobbyTown and practiced on a plastic train station that came with the set we get out at Christmas that I never bothered to put together. That station is tough enough to launch saucer style after welding together with Tenex7. After I realized that most of these plastic welders are methylene chloride I wondered how to control such a low viscosity, low boiling liquid, but that applicator is perfect. The control with it is really impressive.
 
cool :)

now, sometimes the touchnflow needle will get clogged, when that happens, let it sit in the tenax for a few minutes, +/-. to melt the clog out.
 
Depending on the type of plastic you use I have had good luck with the superglue gel from dollar stores.

I found a really good way to glue fins to abs or pvc pipe is to glue the fins on with 5 min epoxy and finish with fillets. After the epoxy has set up rip the fins off they don't hold that well and then re-glue them on with super glue. The extra surface contact you get from the under side of the fillet makes a really strong bond.
 
XrayLizard said:
cool :)

now, sometimes the touchnflow needle will get clogged, when that happens, let it sit in the tenax for a few minutes, +/-. to melt the clog out.
Click to expand...

That happened once, and I just let it hang out for about 5 min in the bottle, and the liquid started rising in the tube again. If every $9 tool I bought worked that well I'd be thrilled, just a really handy product.
 
I had a 20 year old skywinder that was originally assembled with plain old orange tube testors. It held together through many many many launches without problems. The plastic rotors eventual got brittle and broke but the bonded pieces still held. As a kid I remember accidently melting pieces of my plastic models with testors. I guess the formulae has changed since then?
 
I thought I would share my experience with trying to bond plastic fins to a plastic body tube. I tried the superglue materials and really did not have much success since the glue would break cleanly off the plastic surface with very little force. I also tried the 5 minute epoxies and the same thing occurred, again with the fins breaking off very easily. A few months ago I bought this stuff that I saw on ebay, it was listed as a primer for plastics and I thought I would give it try. It was labeled as Model Builders Plastic Bonding Primer and it worked great, I applied it with a Q-tip on the fins and body tube, let it dry for an hour and then used a 5 minute epoxy, I think it was Gorilla brand. After the primer stuff had dried on the fin, I tried to scratch it off with my fingernail and couldn't chip it off. It worked great for me.
 

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