best glue for stainless steel.

[Kirk Gittings]

So I won't go into too much detail because it don't really matter I think, but my film holder for washing sits in a deep stainless tank. I need to glue a pvc pipe array directly onto the bottom to distribute the water evenly (if it sits any higher the film sticks out of the wash water or if there is anything like a screw head on top of the PVC pipe it pushes the film carrier up too). I have noticed over the years, when I glue the "feet" onto the bottom of the tank with super glue or silicone that it doesn't last. I have to re-glue one or two every few months if I use super glue or silicon (and that is with a thorough cleaning and sanding of the SS contact area). I have always thought this adhesive failure must be from expansion/contraction of the SS. Am I wrong about that assumption or is it something else? Anyway is there a better adhesive for gluing plastic to SS in a periodically wet environment? Is epoxy better?

[vinny]

Stainless is impervious to most everything but I'd try epoxy even though epoxy doesn't stick to pvc all that well.
Bolts or screws with rubber washers would be permanent.

[Kirk Gittings]

Stainless is impervious to most everything but I'd try epoxy even though epoxy doesn't stick to pvc all that well.
Bolts or screws with rubber washers would be permanent.

Thanks. Its hard to explain but bolts and screws are a no go in this situation. I made it work half assed that way for the last 20 years, but it means I have to flip the film half way through the wash as the film at one end of the washer just ever so slightly breaks the surface on one end. I have pulled this puppy apart to redo it just to get the film deeper but it really needs adhering the pipe system directly to the bottom of the tank if at all possible. And even so I would like a better adhesive for the feet too.

[Drew Wiley]

There are a number of good epoxies, but my basic go-to product for this kind of problem would be PC-11 marine epoxy. It's a 1:1 paste, which is actually sold in
back to back 35mm plastic film canisters! But the color is white, if you don't mind that. "Super glues" all pretty much fail at this kind of thing. Be sure to give a
little "tooth" to the PVC in particular with a bit of sandpaper action.

[DannL]

Maybe RTV Silicone (aka clear silicone) as used with putting together aquariums. I think the clear pure silicone adhesive sold in Lowes/Home Depot/Wallymart as a sealant for windows/bathroom stuff is the same. Run a test glob, and let it dry for a day or two.

[Kirk Gittings]

White offends my aesthetic sensibilities........:) No actually I could give a crap about how it looks. I will look up the PC-11. THANKS!

[Kirk Gittings]

Maybe RTV Silicone (aka clear silicone) as used with putting together aquariums. I think the clear pure silicone adhesive sold in Lowes/Home Depot/Wallymart as a sealant for windows/bathroom stuff is the same. Run a test glob, and let it dry for a day or two.

Sorry I should have added this. I have not had good luck with the silicone on the feet-doesn't last more than a couple of months.

[Jac@stafford.net]

E6000 industrial adhesive.

[Richard Wasserman]

I have had good luck with acrylic adhesives bonding dissimilar materials. It is more not quite as strong as epoxy, but resists peeling better. The downsides are it is not cheap and requires an applicator gun.

http://www.mcmaster.com/#high-strength-adhesives/=w1u0lg

[Tin Can]

There are very strong double sided construction quality tapes that will work. Maybe somebody can send you a couple inches of that type tape.

Perhaps double sided carpet tape would also work. Maybe not.

RTV is messy, a nasty odor when uncured and really bad for eyes. I hate the stuff. I used to handle 55 gallon drums of it.

Epoxy won't stick for long.

However roughing up the stainless surface with sand paper and then cleaning with acetone may improve bond.

http://www.mcmaster.com/#fastening-tape-with-adhesive-on-both-sides/=w1udfi

[jp]

On lobsterboats (made of fiberglass and stainless) we use 3m 5200 adhesive. Get a small tube and try it.

[Kevin Crisp]

The 3M Marine adhesives for bellow the water line are good, there is a rapid set and one that takes about a week. Rough up the stainless footprint for it.

I know good old JB Weld (sets up overnight -- hard) will stick well to stainless. If it covers a portion of the plastic tube it will dry hard and hold it.

[Bruce Barlow]

Ask Richard Ritter. He'll know, and I'd trust his advice.

[DrTang]

JB Weld?

[Michael Rosenberg]

Kirk,

There is an epoxy called Liquid Steel. My father used it back in the 60's to repair a hole in the water jacket of a car engine! I have used it a couple of times to bond metal together. I think you can buy it at Lowes and Home Depot.

Mike

[Eric Woodbury]

Goop. That sticks to everything. Doesn't matter which one, all the same. Try to burnish the stainless a bit so it has a tooth that will 'grab' the glue better. Clean all with alcohol first. Alcohol is the cleanest of the solvents.

[Drew Wiley]

Just trust me on this one. I sell more specialized epoxy and such per week than most of you will see in a lifetime. The CORRECT epoxy will last for decades. Silicone, incl RTV sealants are short-term fixes at best, and might contaminate solution. In fact, any silicone residue has to be thoroughly removed for anything else to bond. I've even got stainless dkrm trays with corners epoxied rather than welded which were probably a couple decades old when I bought them used, and are still functioning perfectly. Doing metal to PVC or ABS pipe is a rather routine problem. You don't have to be a darkroom worker to encounter it! There are products for these things! No "Goop" either. If you need something clear that holds up relatively long term in water, I know what to recommend; but marine or
plumber's epoxy is better in this instance.

[Drew Wiley]

JB Weld is always handy to have around. I just like the way marine epoxies build up faster and thicker. Plus they're designed to even cure underwater. I've seen JB chip off plastic pipe. The thin build-up seems more susceptible to differential expansion/contraction coefficients, esp around hot water.

[Dan Fromm]

Kirk, funny you should ask. I have a 130 gallon stainless steel aquarium. Roughly a cube with a piece of glass held to the front with silastic. It came with a hole bored in the bottom. I've put a stepped piece of PVC pipe in the hole so I could plumb it to the drains, used JB Waterweld (an epoxy putty) to seal the gaps and hold the PVC in place. Put it in in late '80. The tank's been in use continuously since then. No problems so far.

[sanking]

OK, I trust Drew's knowledge of epoxy. I know a lot about it also, but for this application I would personally use 3M Marine Adhesive Seal 5200, not epoxy. Fit the two pieces together with a good layer of 5200, and don't tighten down until the 5200 sets, which might be a day or two. Sand both surfaces before applying.

You can get buy 5200 in several colors, including white, black and tan, if that is of any importance.

Sandy

[Drew Wiley]

This discussion can kinda revolve around common hardware store products, or if you're a purist, go anywhere you wish. Every morning I drive right past a sizable plant that specializes in the manufacture of marine epoxies. They got gosh knows how many tens of thousands of gallons of chemical ingredients in maybe seven giant storage tanks outside that building, enough to blow up half the city I'd guess. The owner's brains are pretty well fried by all those fumes; otherwise, I'd ask his own opinion. But I've heard it before, and don't care much for the added sermon about mankind's psychological ills due to some nuclear war several million years ago. There a several huge marine dealers around here who keep on hand dozens of kinds of sealants and epoxies. I have a direct distribution account with 3M and sell their Marine Sealant here too. All kinds of goodies I can sample from. Any number of them will work fine. Most ordinary caulk or glue won't.

[vinny]

This discussion can kinda revolve around common hardware store products, or if you're a purist, go anywhere you wish. Every morning I drive right past a sizable plant that specializes in the manufacture of marine epoxies. They got gosh knows how many tens of thousands of gallons of chemical ingredients in maybe seven giant storage tanks outside that building, enough to blow up half the city I'd guess. The owner's brains are pretty well fried by all those fumes; otherwise, I'd ask his own opinion. But I've heard it before, and don't care much for the added sermon about mankind's psychological ills due to some nuclear war several million years ago. There a several huge marine dealers around here who keep on hand dozens of kinds of sealants and epoxies. I have a direct distribution account with 3M and sell their Marine Sealant here too. All kinds of goodies I can sample from. Any number of them will work fine. Most ordinary caulk or glue won't.
We all realize you know your shit. I'm not sure how that rant helps Kirk.

[Tin Can]

I think Drew means the Chem disaster owner rants a lot, and he has heard it too many times.

I had to read it twice.

California.

[Kirk Gittings]

OK, I trust Drew's knowledge of epoxy. I know a lot about it also, but for this application I would personally use 3M Marine Adhesive Seal 5200, not epoxy. Fit the two pieces together with a good layer of 5200, and don't tighten down until the 5200 sets, which might be a day or two. Sand both surfaces before applying.

You can get buy 5200 in several colors, including white, black and tan, if that is of any importance.

Sandy

Thanks. I'm tempted to give this a try.

[Liquid Artist]

I know that it's permanent, but could your local welder just weld a flange on?

[Kirk Gittings]

Thank's, yes I'm sure that route would work, but a little overkill maybe.

[Kirk Gittings]

OK, I trust Drew's knowledge of epoxy. I know a lot about it also, but for this application I would personally use 3M Marine Adhesive Seal 5200, not epoxy. Fit the two pieces together with a good layer of 5200, and don't tighten down until the 5200 sets, which might be a day or two. Sand both surfaces before applying.

You can get buy 5200 in several colors, including white, black and tan, if that is of any importance.

Sandy

So this is what I am trying. Interesting stuff-sort of like a denser stickier silicone sealant. You have to be careful applying it as it seems to get on everything and is resistant to removal. I'll report back in a few months and let people know if it is holding up.

[Richard Wasserman]

Yes, please do let us know how it works out. I was not familiar with 3M 5200 and after reading more it sounds like an excellent choice for your application. The breadth and depth of knowledge on this forum is simply wonderful!



So this is what I am trying. Interesting stuff-sort of like a denser stickier silicone sealant. You have to be careful applying it as it seems to get on everything and is resistant to removal. I'll report back in a few months and let people know if it is holding up.

[Drew Wiley]

The "official" way to do it is through specially gasketed chem-inert thru-couplings, but these are simply not available except via specialty industrial piping suppliers. I had the good fortune of a major supplier being right across the street and knowing them and getting things vastly below catalog price. Otherwise, you
might nor might not be able to find the right thing through McMaster Carr. Overkill, really... but if looks count ...

[Kirk Gittings]

Yes, please do let us know how it works out. I was not familiar with 3M 5200 and after reading more it sounds like an excellent choice for your application. The breadth and depth of knowledge on this forum is simply wonderful!
Part of the reason I went this route is because I think expansion/contraction of the SS was possibly involved with my repeated failures before and 5200 remains a bit flexible when cured. I have to say after just a couple of hours it appears to be damn strong and flexible but I will wait the recommended 24 before really giving it a real spin.

[Kirk Gittings]

The "official" way to do it is through specially gasketed chem-inert thru-couplings, but these are simply not available except via specialty industrial piping suppliers. I had the good fortune of a major supplier being right across the street and knowing them and getting things vastly below catalog price. Otherwise, you
might nor might not be able to find the right thing through McMaster Carr. Overkill, really... but if looks count ...

they don't

[Drew Wiley]

Just remember that with all these sealant type things, cure time might be substantially longer than "apparently dry" time. Wait as long as you can until immersion. Some of the instructions can be misleading because they might be based upon emergency rather than ideal usage. I haven't looked up the specifics on this 3M product, but you get the drift anyway. Or maybe all of this is just my Freudian slip, because I am myself currently re-gluing, re-attaching, and re-painting all kinds of things in the darkroom in a major maintenance overhaul.

[Neal Chaves]

I used PC7 successfully on stainless steel. Here are some views of my 4X5 film washer, made from a stainless gun blueing tank from Brownell's. The washer overflows from two holes near the top on the end, but also siphons off the bottom with rubber hose. The plastic siphon valve is glued to the tank with PC7. The hose is sealed to the valve with a tie wrap hose clamp and some RTV. The hose is notched at the bottom foe water flow. 129973129974129975

[Kirk Gittings]

how long has that PC7 bond been on there?

[Neal Chaves]

how long has that PC7 bond been on there?

At least five years. I prepped both the tank and the valve by sanding.

[Kirk Gittings]

Me too-every time. I wonder if I have a different type of SS that is harder to stick too.

[sanking]

Me too-every time. I wonder if I have a different type of SS that is harder to stick too.


If you allow the 5200 sealant to cure for a week or so I am pretty sure it will stick to any SS. In your case I would imagine the weak link will be the bond to PVC, not to SS.

Sandy

[Kirk Gittings]

The 5200 is looking good so far but I have no problem waiting a week.

[Kevin Crisp]

I've used 5200 to seal stainless fittings to fiberglass boats and it is very durable. Just watch the set time.

[Kevin Crisp]

As I recall there are two versions of the 3M product, fast cure and one that takes the better part of a week. The slow cure is stronger, I think the tube has blue writing on it, the fast cure has red. Neither lasts a long time after you open the tube unless you keep it in a bag in the fridge.

[Kirk Gittings]

I've used 5200 to seal stainless fittings to fiberglass boats and it is very durable. Just watch the set time.

I will wait a good week. In the mean time I set about cleaning some slop off of the stainless steel, the PVC and some rubber. This stuff is very tenacious on all three-much more so than anything I have used in the past.

[Kevin Crisp]

It doesn't matter how careful you are, it transports to your hands, your clothes, etc.

[Kirk Gittings]

It doesn't matter how careful you are, it transports to your hands, your clothes, etc.

yep

[Drew Wiley]

I once worked beside an ex-NASA engineer who was telling me stories about when the first cyanoacrylate "super glues" were being formulated. They'd walk around
the lab telling their co-workers, "hey, feel this stuff", and they'd naturally feel it between their fingers, then somebody would have to come around and gently
work a razor blade between their stuck fingers. It became quite an office joke apparently. Lots of these specialty sealants are analogous. The only solvents that
will remove them can be pretty nasty on your skin. Nitrile gloves, always.

[Jac@stafford.net]

I once worked beside an ex-NASA engineer who was telling me stories about when the first cyanoacrylate "super glues" were being formulated. [...] Nitrile gloves, always.

And never, ever wear cotton gloves. It burns away!
.

[Tin Can]

I once worked beside an ex-NASA engineer who was telling me stories about when the first cyanoacrylate "super glues" were being formulated. They'd walk around
the lab telling their co-workers, "hey, feel this stuff", and they'd naturally feel it between their fingers, then somebody would have to come around and gently
work a razor blade between their stuck fingers. It became quite an office joke apparently. Lots of these specialty sealants are analogous. The only solvents that
will remove them can be pretty nasty on your skin. Nitrile gloves, always.

We did that do. We had a private label chem line of most goo's. Later Loctite bought the line and eradicated it...

[sanking]

As I recall there are two versions of the 3M product, fast cure and one that takes the better part of a week. The slow cure is stronger, I think the tube has blue writing on it, the fast cure has red. Neither lasts a long time after you open the tube unless you keep it in a bag in the fridge.

I have a half-full/half-empty tube (3 fl oz) tube of the Blue version that was opened and used about 1.5 years ago, not opened since then, and stored at room temperature. From squeezing the tube I believe that it is still good, and plan to use it on a new project soon. It did take a very long time to cure, at least a week as I recall.

Sandy

[Nodda Duma]

Professionally, we use 3M 2216 or 1838 epoxy for bonding metals and plastics in assemblies quite often. I've seen the bond joints survive high-speed Impact tests. In fact the only time I've ever seen it fail was under long-term exposure to the hydraulic fluid used on submarine periscopes.

1 hour working time, 24 cure-to-handling time, 7 day full cure at room temperature.

[Duolab123]

3M VHB double sided tape. 3M rep refers to it's strength as having the "Grim grip of Death", pressure sensitive so when you apply clamp it down for 3 or 4 minutes, thin steel sheet metal (5-10 mil) will tear before this stuff will let go. Tell 3M you want a sample and they will usually send you 5 or 6 feet (if you are nice), a company I worked for used 1 in strips of this to fix plate glass weighing 30 lbs or more to powder painted steel, worked great. You need to look for adhesives intended for low surface energy applications!

[swmcl]

Sikaflex.

Black polyurethane glue that sticks the decals on your car and nearly everything else. Don't try to get it off though.

[Tom Schaefer]

late to the party but 3m 5200 is great stuff

[winterclock]

So did the 5200 work? Just curious, I have used it on titanium parts and it seemed to seal well.

[Kirk Gittings]

So far so good but by this time the super glue or the silicone would still be holding too. I need to wait another couple of months really before I can say anything definitive.

[sun of sand]

My guesses have been mentioned but maybe golf shaft epoxy

Maye in 9 months can try em all

[mdarnton]

I haven't followed this thread since the first page, but did anyone mention this stuff?
http://kk.org/cooltools/archives/23798#disqus_thread
This line seems particularly relevant: "The demo that convinced me was a quarter stuck to a PVC pipe that could be bent with pliers without the Plast-Aid releasing."

[HMG]

Yes, please do let us know how it works out. I was not familiar with 3M 5200 and after reading more it sounds like an excellent choice for your application. The breadth and depth of knowledge on this forum is simply wonderful!

I realize this thread is a year old, but I see that a 10oz tube of 3m 5200 is on sale for under $15 at Amazon (http://www.amazon.com/3M-5200-Adhesive-Sealant-cartridge/dp/B0000AY6AC?ie=UTF8&ref_=pe_837390_188109290_dotd_8_t_5).

[Drew Wiley]

The more valid question is whether the caulk itself is over a year old! Better to pay more for something fresh from a specialty dealer. The shelf life of many of
these products is rather limited.

[HMG]

The more valid question is whether the caulk itself is over a year old! Better to pay more for something fresh from a specialty dealer. The shelf life of many of
these products is rather limited.

True. I don't know if the tubes are dated or you can tell via lot number (certainly 3m can, but not necessarily the consumer). Any idea?

Baring that, the best is whether it's from a source with high turnover. As a rule, if it's sold by amazon, I think it's likely not to be old. But if it's sold through Amazon, all bets are off. If concerned, a marine store with high turnover might be best.

[Neal Chaves]

Here are some photos of my 4X5 film washer for films in hangers. It is a stainless steel gun bluing tank from Brownell's. I place it under a faucet in my sink. Water runs through and exits from overflow holes at the opposite end. A plastic valve is mounted at the end of the tank with JB Weld, and inside a rubber hose siphons water off the bottom. I roughed up both the tank surfaces and the valve with sand paper before gluing several years ago and it is still holding tight.149061149062

[plapczynski]

Can I say something stupid. Have you tried a magnet? There's all kinds of options if a magnet sticks.

[Drew Wiley]

Simple answer. Stainless steel is not magnetic. And rubberized steel or magnets don't tend to be very strong. Anything non-rubberized will quickly rust.

[Kirk Gittings]

So did the 5200 work? Just curious, I have used it on titanium parts and it seemed to seal well.

The 5200 is the best glue I have come across for many applications. It has kicked butt on my SS application that started this thread and many other uses too. Amazing stuff. The only drawback is its slow cure time but I have learned to be patient and live with that. I keep a tube of the white and the black on hand at all times.

[Nodda Duma]

You can usually accelerate the cure of 2 part epoxies with elevated temperatures (i.e. curing at 50C)

[Kirk Gittings]

The 5200 is not an epoxy but a super tough/sticky marine glue that dries flexible sort of like silicone but much tougher and stickier. My impression is that it will cure quicker in a humid environment so with small parts I bag them and spray a lick of water in the bag.

[Drew Wiley]

For fast cure times a new category of moisture-cure polyether sealants has shown up on the block. What I hate about them, however, is that they feel perpetually
sticky and attract dirt and stains like crazy. So if you thought amidol fingernail stains were ugly ....

[Kirk Gittings]

For fast cure times a new category of moisture-cure polyether sealants has shown up on the block. What I hate about them, however, is that they feel perpetually
sticky and attract dirt and stains like crazy. So if you thought amidol fingernail stains were ugly ....

The fast cure 3M 5200 marine adhesive/sealant nor the slow cure does not feel perpetually sticky in my experience unless it is not fully cured. Once fully cured it feels just like cured silicone sealant.

[Drew Wiley]

Yes indeed; but I don't particularly care for cured silicone sealant either, even though I just applied some last nite, but more as touch up where I didn't use real
epoxy.

[Kirk Gittings]

And in what circumstance pray tell does it matter how it feels when cured? In most applications I can't even see it and in those I can I have no interest in continuing to feel it. I used to take great pride in my welds when I used to be a welder, but an adhesive? If it looks neat and holds I never look back much less feel it.

[Drew Wiley]

Physical integrity. Things get hooked and scraped etc over time. Sorry if I sound nitpicky; but be right across the road from marinas, this is a daily subject here.
Take your experience of hypothetical issues and multiply that by a thousand, and it becomes real. Or turn your darkroom sink into a twenty million dollar yacht,
then get yelled at when something goes amiss. And heaven help you if that billionaire decides to build a darkroom sink himself, because he'll want to hire a guy
for two dollars an hour to do it.

[Kirk Gittings]

I'm sorry I thought we were talking about photography applications......