High Temperature Adhesive

I'm looking for a strong high temperature (about 860 F) adhesive (don't care what type, just something that holds two parts together) ...

Hi Steve,

will the parts be always hot (460C), or only while doing the glueing ?

This temperature is close to the melting point of aluminum (660C = 1220F)

The adhesive work I'm hoping to do at room temperature, but that's not a requirement. In operation, the assembly will start at outside room temperature (30 F to 100 F) and during flight may reach the 860 F temp. It will then cool down when exposed to the ambient temperature of -60 F to -100 F.

Look on the adhesive manufacturers websites, Google hight temperature adhesives... or don't use it.

If you are joining ali' rod to ali' sleeve maybe shrink the parts together. heat one cool the other, slip 'em together they will then be nice and tight.

If you have access to a furnace, you could possibly braze the aluminium parts together using Nokolok flux. We make aluminium automotive heat exchangers and thats what we use.

Al

Seems you can use it in a flame brazing process so maybe a blow torch would do the trick here's a link http://www.solvay-fluor.com/product/lib/0,0,-_EN-1000196,00.html

what is that Nokolok flux contain? Is it some kind of Aluminum powder based welding flux.

Mixture of Potassium Fluoroaluminates :

KAlF₄ - 80%, K₂AlF₅.H₂O - 15%, K₃AlF₆ - 5%

Al

Very interesting material. As it is it looks an insulating one so how come it works in welding? Some metal grains also may be there in that 100% count. I can easily say that in crystalline or polycrystalline form this will be a good thermoluminescent material but not if there is some good amount of metal like Cd and Ni etc in it.

The compounds I mentioned are the complete make up of the material as per the COSHH datasheet there are no metal grains in it. It is a white powder similar in consistency to talcum powder. Somewhat more abrasive though

Al

Are you heat welding it? I think in that case it will decompose and will leave Aluminum behind. I will try to find out if this thing is available in India.

If you take some powder to gamma irradiation under cancer therapy machine for just few minutes and then put the powder on hot plate at about 250C then you can see a brilliant blue green glow coming out of it. You need about 1000 Rad or 10 Gray gamma dose to see the glow in open light.

Try looking at 3M's website, its a big website, but they do have some informative design spec sheets for finding a adhesive.

Is spot welding out of the question?

Just out of curiosity, do you really need to glue these parts? Could you machine it as one piece of aluminum stock? How big is this thing?

You know best, but an adhesive that can go from -100° F to 860° F without coming apart sounds like quite an amazing substance!

Good luck!

Unfortunately, that's not an option from a size or cost perspective. It's a rocket body, approximately 12 feet long and a foot in diameter.

Say no more! It all makes sense now. Thanks for that piece of info!

I've used ceramic adhesive from Sauereisen to bond heating elements into aluminum housings. They claim that it is ok up to 2600°F. It cures at room temperature but I have no idea how well it would work on sheet material, I imagine it might be a bit too brittle. Check the Sauereisen web site, they have a whole range of adhesives.

Cool site, but what about the -100° F? I didn't read the whole site, but can it stand the temperature swings without becoming brittle? Just curious.

Ceramics are usually pretty good at low temperatures & from what I remember of this adhesive it's basically a ceramic slurry which dries out to leave the base material in the joint. I've only had experience of that one ceramic adhesive so it's worth checking the whole range.

TRY "COTRONICS" THEY MANUFACTURE SEVERAL TYPES OF HI AND LOW TEMPERATURE ADHESIVES

Do turn off the Caps Lock before contacting them, though. One wouldn't want to seem rude by SHOUTING.

For such temperature extremes and the mention of "flight" I would not wish to fall out of the sky. What about welding and rivets?

Even girls do all that for NASA. Why are you so scared?

On a recent Discovery or History channel show, they were doing a story on 3M and some of their leading edge adhesive technologies. One of their testing protocols involved swinging a 16lbs bowling ball at two joined aluminum plates. The benchmark they use is rivets, which typically fail after a few hits. They showed at least one adhesive tape that lasted more than a dozen strikes.

The heat resistence of this tape was not disclosed but as suggested above, refer to the 3M site for a spec sheet. As flight has been suggested, I'm sure a more expensive adhesive tape may be in the budget rather than cheap reliable rivets.

We have used rivets up until now, but the process is very labor intensive, so that and the added weight of the rivet have caused me to look elsewhere for a solution. We are considering spot welding, but some of the spots are difficult to reach. That would be my second choice at this time.

Hello,

Is dry weight a problem once the adhesive is applied? (flight)

I have a substance that can withstand the types of temperature range you are projecting, it will adhear metal to metal or any other surface actually. If you are interested in this product I will give you the details on the product itself. The only concern may be the weight of the bonding agent once it drys.

Let me know if you wish for me to pursue this further if so I will be happy to supply the MSDS info on this product, inorder for you to make an informed decision.

Fusion or Lucas Milhaupt both make brazing pastes with a flux which can be used to bond the two parts. They also could braze the two parts together for you on prototype equipment they have in house. Brazing would be the best way to hold these parts together.

Try the following link: www.masterbond.com. Have used them in the past for ceramic applications. They make the adhesive that bond the ceramic tiles to the space shuttles.

The product I was to introduce will not work in your application.

Get a hold of Hysol aerospace, I can not remember the product number but there are a large number of material selections that can be used in the 860F range. However, materials based in imide chemistry can have very long cures 350 F for 6 hours then post process at 400 F for 8 hours.

Surface prep is everything also. Watch the surface tensions of the boning units.

I would roll the end of the sheet and insert the rod and tack weld the ends.

Hi Steve,

It depends if you are looking for a permanent bond on a temporary one.

If its permanent and this is the the standing service temperature (860F) there are several you can use. Biggest question - what are the loads? If you have some load on it, then try a phenolic. If not, you can use some PSA type adhesives which are modified acrylics.

If its temporary, an acrylic or silicone will work, but again it depends on the load. PSA's (tapes) are quite good, but not often under high load or sheer.

Can you provide more information?

ElCell

I'm looking for a permanent structural adhesive to attach rocket body parts. The temperature comes from atmospheric heating and hense is room temperature to approx 860 F, then back down. the loading is approx. 3000 lbs aft and 4800 psf on the nose.

steve

Dear Steve

Carbon fiber filler with adhesive which becomes Strong on backing and also has high directional strength can be tried. These are often used in formula one cars for high strength, light weight and can take to high temperature as well. Perhaps if you have some experts in your zone who have such facility then visit them. I have seen their documentaries and they wrap around these easily cut cloth like strips to give shape and then back them to make the body solid.

Do not use glass material alone for bonding, even though they may look strong, they may crack also and separate. Somewhat elastic bonding is much better and have less chances of breaking.

Your heat rating is not such a problem, it would be the load which is bigger concern. Depending upon the force against the bond, you could be out of luck. I would look at: http://mae.pennnet.com/whitepapers/wp.cfm?id=153 and see how that might work for you.

My initial thought of a phenolic would take your heat (once activated by heat, it wont flow again by heat), but the force of your load may kill it. If the surface area of the bond is large enough, you may yet succeed with it.

Best of luck.

With the loads your listing you'll need to be prepping your surfaces carefully. Phosphoric anodizing and primer tremendously help with your bonds. Phosphoric anodizing has its downfalls as it is very temperamental to handling to handling damage. If the parts are rubbed in any way before priming you should use chromic anodizing instead.

Priming your surfaces with a suitable primer also tremendously improve bond strengths with any of the polymer adhesives.

Scooter

I was trying to remember the name of a company I cover and couldn't think of it. Then all of a sudden, boom, Infast came to my mind.

When you cover as many as I do you are lucky for anything to come out of the blur.

Thanks for the name, but none of their products seem to be a fit. I'm looking for a permanent structural adhesive to attach rocket body parts.

Steve

So any idea what the military does? Or do they just have the bank to stamp them out or weld fins on?

I've worked for a company that supplied such parts to the military, they just machined them from billets of magnesium, removing 90% of the material in the process. It's not a problem when the taxpayer is picking up the bill.

Yes, I have a pretty good idea what they do, but we aren't tapping the taxpayer's pocket, so we are trying to stay low cost.

This question is for my own curiosity...

I'm imagining that you are one of those model rocketeers that have moved so high up the rungs that you're ready for the BIG-TIME. In other words, you are playing with those rockets that require a degree (I think) and certification from the FAA. Am I correct?

If yes, do you really need fins? If your rocket body is as big as you say it is, what about inertial guidance? What about several gyros instead of fins to stabilize your creation? Diode lasers are getting really cheap and I believe that the plans for very compact laser gyros are unclassified by now.

Any thoughts?

We are a mixed bag of born again rocketeers, and me with 30+ years in aerospace. We have avoided steerable rockets because of the complexity, expense, and the gov't. We have enough interest w/o adding them more into the equation. At some point we will have to go steerable. And yes we talk to the FAA and BATFE a lot. They have been absolutely wonderful. The other TLAs however, have been annoying. Our biggest problem is not technical, but rather the pathetic insurance industry.

Gyro alone wouldn't be enough. Some form of vectored thrusting nozzle would have to be connected to feedback with the gyro positioning, if fins are to be omitted.

Gyro and vectored nozzle feedback would theoretically work at any speed (provided that this real-time feedback is adequately responsive), while fins will only do their job from a minimal speed and upward.

Why not Google for "thermosetting ceramic compound", and / or "high temperature epoxy" ?

"high temperature epoxy" got me epoxies that are good up to about 600 F. I am finding ceramic adhesives that are more what I'm looking for. Thanks.

Would getting the fins welded on to the body really be that expensive?

If you want to be a pioneer, how about connecting the body and fin to a high amperage power supply, then placing powered aluminum and a catalyst between the two, and finally turning on the power to fuse the two pieces together?

Just a thought.

Our customer requires removable fins, so welding is out of the question. Thanks,

Steve

so, how is the hunt going? In quiring minds want to know!

Scooter

I have found several good candidates thanks to you guys. When we get a breather from our CDR, I will be experimenting. I'll fill you in then.

steve

Well, things have improved somewhat. We have discovered that while the stagnation temperature is about 860 F, the recovery temperature which is what we needed to be concerned with is only 530ish. This means that we can use epoxies, ie our previous favorite JB Weld. We will still need to anodize the pieces, which will add to the cost, but the anodizing will create a microscopically textured surface which will bond to the JB Weld better. Surface prep is everything with aluminum. It oxidizes so easily. I feel much more confident with the aluminum at the lower temperature. Thanks again guys.

steve

We appreciate the feedback. sometimes these things just slip into oblivion.

Much luck to you guys

Why do they require removable fins? And if that is true, then you must be looking for a glue that can be overcome by the user, but can still make a flight? If that's the case, what about some sort of fasteners instead?

Sorry if it's a dumb question.

Best solution is to laser weld, laser cut and re-weld using laser. This allow precision shape as laser does welding using short pulses. If laser cutting is a problem then use cold water jet cut. This prevents deformity of the shape due to change gradient and temperature shock.

See post #46.

Other good alternative is to have latch up arrangement as it is done for turbine rotor blades. Insert and latch then by a key.

We have designed a fixture to be permanently mounted and the fins bolted to it.

Steve

This has gone from adhesive to snipe. I learned my lesson long ago, thank you.

Lets see. It can't be molded into design. It has to be magic glued/adhered. It cannot be fastened. It cannot be welded.

hmmmm. Hey, a guy on another thread has a free energy device. I'm goin over there.

cr3

I concur. It's like a guessing game. We throw out the answers, and the originator of the thread say "No, that won't work, either."

Please tell us enough information about how this thing has to work, and we might be able to tell you how to do it. Arg!