What adhesive is suitable for gluing steel and G10 material?

[yungman]

Hi

I need to glue steel with G10 material together. But it is in moving parts environment that constantly see oil for the moving parts. My first thought was epoxy, but can it survive in oily environment in the long term. Any other suggestions?

thanks

Alan

 

[Ranger Mike]

JB weld

 

[yungman]

JB weld

Do you mean epoxy? They have others

Thanks

 

[Ranger Mike]

yes
i am very familiar with two part JB Weld in IC engine applications. never has failed me.
Sealing up and filing space..not good to hold a broken connecting rod.

 

[yungman]

yes
i am very familiar with two part JB Weld in IC engine applications. never has failed me.
Sealing up and filing space..not good to hold a broken connecting rod.

Just to verify, this is the one. I actually have it at home.

Thanks

 

[Baluncore]

I need to glue steel with G10 material together. But it is in moving parts environment that constantly see oil for the moving parts. My first thought was epoxy, but can it survive in oily environment in the long term. Any other suggestions?

Your unspecified temperature range will be very important with organic glues.
Some plastics absorb water and/or oil. They swell and distort, physically breaking the adhesive bond.

For cool environments (≤110°C), and with the right shape plastic, I wind a Kevlar thread around the object, in an open cross-hatch pattern. If that is done while the object is cold, and then wetted with glue, it becomes a constrictive exoskeleton when the plastic expands at operating temperature.

 

[sophiecentaur]

Is drilling and tapping out of the question? (Threading the steel.)

 

[jrmichler]

If mechanical fastening is not acceptable, I would try:

1) Epoxy. Clean the steel to bare metal, then wet sand with the epoxy. Sand the surface of the G10, coat with epoxy, then assemble.

2) A high performance adhesive, such as 3M 5200 or Surebond SB-190. I have used both, and they really stick to steel and most other materials.

In either case, I would seal the surface with a coat of paint after the adhesive is fully cured.

But my first choice would be mechanical fasteners.

 

[hutchphd]

I wind a Kevlar thread around the object, in an open cross-hatch pattern.

Is Kevlar better than carbon fiber?

 

[Baluncore]

Is Kevlar better than carbon fiber?

I cannot tell. It will depend on the chemical bond between the fibre and the glue. Epoxy bonds reliably with carbon fibre, so does a more expensive repair, that takes longer, but the greater investment lasts for a longer time.

For me, Kevlar is free, because it comes bundled with short lengths of waste optic fibre. It also rapidly wicks and bonds with the cheap cyanoacrylate superglues, that can get a repair done immediately in the field. For example, electrical magneto or switch bodies on tractors fracture and stop the machine. The non-conductive solution is Kevlar, not carbon fibre. The glue must completely saturate the fibre to prevent water ingress later.

Epoxy is a good filler, but not good for close-fitting glue joints. That is because the polymer chains tend to form along the crack, not across it.

Bulk plastics tend to become brittle with time. My aim is to have the cheap brittle plastic become a filler, inside a thin structural exoskeleton. That can significantly extend the life of a product that otherwise does not justify a "forever" fix with more expensive carbon fibre and epoxy.

A bee would use propolis. https://en.wikipedia.org/wiki/Propolis

 

[hutchphd]

I will need to search on the propolis reference.
I have made some remarkable plastic repairs using surface carbon fiber (either linearly applied or chopped and randomly spread) This was occasioned by leftover 4 inch carbon fiber ribbons from a prophylactic vertical surface application on my cement block cellar walls which were starting to try to bow under tension (boy that was an easy fix and has remained solid for a decade now.) I use the surface application technique reqularly on plastic (and even on an Aluminum casting for my snowblower. Works very well.

 

[Baluncore]

I use the surface application technique reqularly on plastic (and even on an Aluminum casting for my snowblower. Works very well.

With an old Stihl chainsaw, with covers made of magnesium alloy, and plastic internals, there is a tendency to crack when trees fall on it. I drilled zigzag lines of 1mm holes on each side of the cracks, laced it both ways with Kevlar, then 5 minute epoxy. The flexibility and acoustic impedance mismatch of the repair must be good, as it has not fractured since, even when it has fallen from trees.

The local Stihl dealer is not happy, because I don't buy a replacement. The old saw is from before the era of the kick-back chain brake, so if I had not fixed it, I would be safer. We have a good long term relationship. I know it secretly wants to kill me, meanwhile, it just loves to cut wood, and to be cared for. They don't make them like they used to.
I keep it keen (with a file) and jealous by having half a dozen other saws, none of which is as universally convenient and reliable.

 

[hutchphd]

You are clearly crazier than me when pushed by exigency. I salute you sir.
The epoxy I got for the basement walls (from some folks in San Diego) was quite extraordinary: very long time constant, low viscosity, and seems to to stick to everything. I don't know enough to characterize the product otherwise, but it is the best. Doesn't like greasy plastic but styrene works and polycarbonate too. This is all voodoo to me, but my house is quite pleased with the result as is the snowblower , as am I.

 

[yungman]

Your unspecified temperature range will be very important with organic glues.
Some plastics absorb water and/or oil. They swell and distort, physically breaking the adhesive bond.

For cool environments (≤110°C), and with the right shape plastic, I wind a Kevlar thread around the object, in an open cross-hatch pattern. If that is done while the object is cold, and then wetted with glue, it becomes a constrictive exoskeleton when the plastic expands at operating temperature.

It's mostly room temp. It's something I carry in my pocket only.

 

[yungman]

OK, this is really what I am using it for. It's for a pocket folding knife.

The knife has G10 scales( outer cover), inside is steel liner on both sides of the blade. The G10 scales are screwed together with the steel liners on the pivot screw and a few screws on the handle. The G10 help to stiffen the handle against prying. I made a mistake of thinning out the area around the pivot area of the G10, so it's so thin that it's not good enough to stiffen the handle up.

What I am trying to do is to glue the G10 scales close to the pivot area to the steel lines so they become one piece to be stronger. The thing is I need to oil the pivot as the blade has to flip open and close.

It's going to be in my pocket when I go out, that's it. It's not any deep science, just I want to beef up the knife.

If the KB epoxy I showed is good enough for the purpose, that it can survive in oily environment, that's all I need.

Thanks

 

[Ranger Mike]

Yes this is the stuff...i use it on engine blocks for race cars. Water passage block. has never leaked or failed with many years heating and cooling. can be drilled but tapping not recommended. You can surround a threaded insert and it will hold in moderate applications. EVERY crew chief I know has this in the pit box.

 

[yungman]

Hi

I complete it, it feels very secure. Now my question is what stuff should I avoid to keep the epoxy in good shape? Particular chemicals that dissolve epoxy.

thanks

 

[Baluncore]

Now my question is what stuff should I avoid to keep the epoxy in good shape? Particular chemicals that dissolve epoxy.

Avoid heat, UV light, ozone, and chemicals used as paint strippers, such as caustics and nasty things like chloromethane.

 

[yungman]

Hi

Thanks for the help, works great.

I have a follow up question. The JB Weld seems to stay soft and sticky for a while, at least like 15mins or longer. I wonder how long after they are mixed that I can still make slight adjustment and not hurt the final bonding?

Thanks

 

[yungman]

I just learned an expensive lesson that JB Weld do NOT work on G10 material. I tried to glue G10 to stainless steel, it just literally peel off.

I cleaned the surface to get rid of all oil, I use lighter fluid, then use soldering flux removal to clean the surface very clean. I clamped them together tightly, waited for 12hrs to set before even touching it. It was in room temp. I don't think the epoxy is bad as it glued tight onto the steel part, I cannot even scrape it off the steel. So it got to be the G10 problem. Now the question is how can I save this and what other glue to use.

1) How can I save what I have now, that the steel is covered with epoxy. Now to save this, I have to glue the epoxy covering steel to the G10. Literally gluing the solid epoxy to G10. The epoxy form a very tight shape to the surface G10, I might get a very good contact on this one.

2) For future, what glue should I use to glue steel to G10?


Thanks

 

[Baluncore]

You can glue the G10 to the epoxy with a different glue.
What bonds to G10? Cyanoacrylate?

You may do better, if you physically scrape the surface of the G10 with a blade to prepare the surface, than by using organic chemicals that may change the molecules at the surface. Methylation, for example, can prevent the ends of polymer chains from bonding.

You can start again by releasing the epoxy from the steel by heating to over 150°C.

 

[yungman]

You can glue the G10 to the epoxy with a different glue.
What bonds to G10? Cyanoacrylate?

You may do better, if you physically scrape the surface of the G10 with a blade to prepare the surface, than by using organic chemicals that may change the molecules at the surface. Methylation, for example, can prevent the ends of polymer chains from bonding.

You can start again by releasing the epoxy from the steel by heating to over 150°C.

The surface of the G10 is rough already.

I use lighter fluid(Ronson)
https://www.amazon.com/gp/product/B0017X1NGO/?tag=pfamazon01-20

then use flux cleaner
https://www.amazon.com/gp/product/B005DNQWV0/?tag=pfamazon01-20

The epoxy has no problem sticking strongly on the steel.

 

[yungman]

What bonds to G10? Cyanoacrylate?

That's what I am thinking, super glue. The dry epoxy has the surface pattern of the G10, meaning I can get a very close matching surface.

One thing is the finish product might be bend slightly during use, I heard super glue is not good in lateral movement.

 

[Baluncore]

The surface of the G10 is rough already.

Roughness is not an advantage with a chemical bond.

I understand that G10 material is an epoxy, reinforced with glass fibre. Cleaners make the surface of the epoxy less chemically reactive, and soak into the glass fibre.

That is why I suggest mechanically scraping the surface to expose fresh epoxy and glass to the adhesive.

 

[yungman]

Roughness is not an advantage with a chemical bond.

I understand that G10 material is an epoxy, reinforced with glass fibre. Cleaners make the surface of the epoxy less chemically reactive, and soak into the glass fibre.

That is why I suggest mechanically scraping the surface to expose fresh epoxy and glass to the adhesive.

I am going to try super glue and see.

Thanks

 

[yungman]

Roughness is not an advantage with a chemical bond.

I understand that G10 material is an epoxy, reinforced with glass fibre. Cleaners make the surface of the epoxy less chemically reactive, and soak into the glass fibre.

That is why I suggest mechanically scraping the surface to expose fresh epoxy and glass to the adhesive.

I am confused, I used epoxy for two different pieces of G10 to steel, I checked the other piece where I have loose epoxy in the surface of the G10, IT STUCK ON VERY STRONG, I cannot even scrape it off the surface of the G10. I tries to bend the G10 to separate it from the steel, it won't. That's exactly what I expect it to do.

Just that one piece like that. Why?

 

[Baluncore]

Just that one piece like that. Why?

There are things like waxes in monomer resins that migrate to the surface as it polymerises. Those chemicals are not removed by the cleaning process. Your cleaning process adds more chemical contamination to the surface.

Believe me, the surface of G10 needs to be mechanically scraped to remove the external surface chemistry.

Epoxy loves epoxy. Use a hardback razor blade, scrape away all the surface chemistry, all the way down to epoxy and glass. Keep it dry until you wet it with the new epoxy.

 

[yungman]

There are things like waxes in monomer resins that migrate to the surface as it polymerises. Those chemicals are not removed by the cleaning process. Your cleaning process adds more chemical contamination to the surface.

Believe me, the surface of G10 needs to be mechanically scraped to remove the external surface chemistry.

Epoxy loves epoxy. Use a hardback razor blade, scrape away all the surface chemistry, all the way down to epoxy and glass. Keep it dry until you wet it with the new epoxy.

But I did all the cleaning at the same time one piece after the other, why one pieces seems to glue tight, the other just literally fell off, like I just peel them apart.

Same step cleaning one piece after another.

I have to open up some one ones I did before and try to peel them apart, I have quite a few sets. I'd be a lot more convinced if other fail also.

I'll be back after trying more.

 

[Tom.G]

How can I save what I have now, that the steel is covered with epoxy. Now to save this,...

Methylene Chloride will strip epoxies... and paint from surfaces, oil from metal, bark from trees, and skin from bone. It is sold in hardware stores as paint remover or paint stripper.

Use it outdoors and stay upwind. Legal disposal could be a problem.

[edit:] It at least used to be sold as a degreaser in spray cans in automotive supply stores.

 

[Baluncore]

Just stop overthinking it, and scrape the surface.

 

[yungman]

Just stop overthinking it, and scrape the surface.

I have to get back to you. I open another one, feels like the epoxy doesn't even stick onto the steel that well, when I peel it, half stick on the steel, half on the G10

Now I question the epoxy whether it's too old or not good enough. It's less than 2yrs old.

I'll be back.

 

[docnet]

Hi

I need to glue steel with G10 material together. But it is in moving parts environment that constantly see oil for the moving parts. My first thought was epoxy, but can it survive in oily environment in the long term. Any other suggestions?

thanks

Alan

isn't G10 itself made of epoxy? not trying to be smart, just pointing out what could be a problem.

 

[yungman]

Just stop overthinking it, and scrape the surface.

I finally get a chance to try this.

I scraped both the surface of G10 and even the metal surface.

IT WORKED. THANKS.