Posted Wed Dec 26, 2012, 7:28am Subject: Request for help in handyman project stainless steel adhesive
One does not have to belong to Coffeegeek very long to discover that most active members are engineering- or mechanics-capable and a lot of experience is present among them. Therefore I am in excellent company to pose the following problem.
Problem: The four spot welds that held a SS flange onto a SS mixing bowl on my Kitchen Aid mixer recently failed. Bowl and flange are not distorted or damaged otherwise.
Attempt: Mating surfaces of bowl and flange prepped with a small drill-mounted grinding stone until shiny, then wiped with a clean tissue, then 5 minute epoxy thoroughly mixed and apply liberally. Parts positioned and compressed with a hand-tightened C-clamp using medium small plastic pad to protect bowl inner surface.
Result: Flange could be pulled off by hand in 24 hours. My first suspicion is that the epoxy was a low quality product.
Question #1: I can chip off the brittle epoxy from the convex surface of the bowl with a chisel, but the concave surface of the flange is too small and awkward for this maneuver. How best to remove epoxy from the flange? Using grindstone or wire brush promises to heat up the residue, producing an unremovable film from the flange, stone and brush.
Question #2: How best to effect a good quality adhesion of these parts? I have often seen JB Weld mentioned in this forum, but I have no experience in its use and do not know if it has tensile strength. Also, product should be available in 30 ml quantities or smaller - this is a one-time project. NB: a replacement bowl has been purchased and is on the way. This project is for learning. The cost of having this re-welded is likely to be too much.
Superfluous editorial: the rise of big box home improvement stores with inexperienced employees has eclipsed the existence of experienced handymen in most communities. Advice such as I am asking for is hard to find.
germantownrob Senior Member Joined: 2 Dec 2007 Posts: 2,018 Location: Philadelphia Expertise: I love coffee
Espresso: Duetto 3, A Dead Oscar Grinder: Vario-W, Preciso w/Esatto,... Drip: Brazen Roaster: Diedrich IR-1, HT B
Posted Wed Dec 26, 2012, 8:33am Subject: Re: Request for help in handyman project stainless steel adhesive
If the epoxy is fully cured then it should not get soft again. If that epoxy failed you should do your very best to remove all you can so your new bond will be metal to metal. I have used many of the JB weld products to do some pretty serious bounding, they make many variations so have a look at their website to determin which may be the best for your application, might want to check out marine since it sounds like this is the bowl that will get washed and if like me ends up in the dishwasher.the biggest problem I have encountered with joining to pieces of metal that need to be able to handle torque is that it leaves very little space for epoxy to be after clamping, jb weld is very strong but if the layer is so thin then it will likely just break again. Two part epoxy is sold in the containers it is sold in but it will keep a very long time and it is always good to have some around. I do not recommend quick dry for this application, seems it trades off strength for speed.
emradguy Senior Member Joined: 31 Mar 2011 Posts: 1,726 Location: Houston Expertise: I live coffee
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Posted Wed Dec 26, 2012, 8:58am Subject: Re: Request for help in handyman project stainless steel adhesive
Buckley Said:
Question #1: I can chip off the brittle epoxy from the convex surface of the bowl with a chisel, but the concave surface of the flange is too small and awkward for this maneuver. How best to remove epoxy from the flange? Using grindstone or wire brush promises to heat up the residue, producing an unremovable film from the flange, stone and brush.
Question #2: How best to effect a good quality adhesion of these parts? I have often seen JB Weld mentioned in this forum, but I have no experience in its use and do not know if it has tensile strength. Also, product should be available in 30 ml quantities or smaller - this is a one-time project. NB: a replacement bowl has been purchased and is on the way. This project is for learning. The cost of having this re-welded is likely to be too much.
JB weld rocks, but it's ugly. Also, as Nobby said, it's best when used with a bit of bulk, so if the layer is too thin, I probably wouldn't count on it either. I'd rough up the contacting surfaces as well to help get a stronger bond no matter what product you end up with.
Posted Wed Dec 26, 2012, 12:08pm Subject: Re: Request for help in handyman project stainless steel adhesive
Than ks, guys. Sure...sandpaper! Of course. The best thing I learned from both of you is to leave it thick - I always thought that thinner was better - for no reason.
Posted Wed Dec 26, 2012, 5:18pm Subject: Re: Request for help in handyman project stainless steel adhesive
Buckley Said:
One does not have to belong to Coffeegeek very long to discover that most active members are engineering- or mechanics-capable and a lot of experience is present among them. Therefore I am in excellent company to pose the following problem.
Problem: The four spot welds that held a SS flange onto a SS mixing bowl on my Kitchen Aid mixer recently failed. Bowl and flange are not distorted or damaged otherwise.
Attempt: Mating surfaces of bowl and flange prepped with a small drill-mounted grinding stone until shiny, then wiped with a clean tissue, then 5 minute epoxy thoroughly mixed and apply liberally. Parts positioned and compressed with a hand-tightened C-clamp using medium small plastic pad to protect bowl inner surface.
Result: Flange could be pulled off by hand in 24 hours. My first suspicion is that the epoxy was a low quality product.
Question #1: I can chip off the brittle epoxy from the convex surface of the bowl with a chisel, but the concave surface of the flange is too small and awkward for this maneuver. How best to remove epoxy from the flange? Using grindstone or wire brush promises to heat up the residue, producing an unremovable film from the flange, stone and brush.
Question #2: How best to effect a good quality adhesion of these parts? I have often seen JB Weld mentioned in this forum, but I have no experience in its use and do not know if it has tensile strength. Also, product should be available in 30 ml quantities or smaller - this is a one-time project. NB: a replacement bowl has been purchased and is on the way. This project is for learning. The cost of having this re-welded is likely to be too much.
Superfluous editorial: the rise of big box home improvement stores with inexperienced employees has eclipsed the existence of experienced handymen in most communities. Advice such as I am asking for is hard to find.
Is it possible to drill a 1/8" hole through each area that was spot welded and secure with a stainless steel rivet? (you will need a rivet gun ... about $6 from harbor freight). That would be the most secure way of doing it besides spot welding. JB weld has its purposes and I consider it to be about the best epoxy around, but it just doesn't like the constant vibrations that your application likely puts forth.
Len
"Coffee leads men to trifle away their time, scald their chops, and spend their money, all for a little base, black, thick, nasty, bitter, stinking nauseous puddle water." ~The Women's Petition Against Coffee, 1674
troposcuba Senior Member Joined: 20 Nov 2012 Posts: 8 Location: Tucson Expertise: I live coffee
Posted Wed Dec 26, 2012, 6:26pm Subject: Re: Request for help in handyman project stainless steel adhesive
CoffeeRoastersClub Said:
Is it possible to drill a 1/8" hole through each area that was spot welded and secure with a stainless steel rivet? (you will need a rivet gun ... about $6 from harbor freight). That would be the most secure way of doing it besides spot welding. JB weld has its purposes and I consider it to be about the best epoxy around, but it just doesn't like the constant vibrations that your application likely puts forth.
I am an aircraft structural mechanic. I make any metal part of just about any aircraft you can imagine. I also do repairs where we cut out damage and make new parts and rivet it all back together. If it were mine and I didnt' feel like welding it, I would just shoot some stainless rivets back in there. The kind that Len is talking about is basically a pop rivet. They are not as strong as a solid rivet would be, but you are gonna have a tough time installing solid rivets without the tools required. Your best bet might be finding a local welder that does TIG welding and have them weld it back on (they can fill the hole while they are at it. Any of your good epoxy adhesives should work as long as it is mixed properly and cured well (you can use some heat to help it cure up). A smooth shiny surface is gonna make it difficult for the epoxy to adhere. You want a little bit of a rough surface for the epoxy to stick to. Some 80 grit sandpaper would do nicely. The pop rivets would be my last choice as they are not that strong.
Posted Wed Dec 26, 2012, 9:58pm Subject: Re: Request for help in handyman project stainless steel adhesive
Yeah...I have my doubts about the permanence of epoxy. That is why a new bowl is on the way. This is a project to explore the feasibility of home-repairing a mixer bowl that does take a significant amount of knocking about when kneading with the dough hook. The pop rivets should last longer than the epoxy but I have had experience with them loosening with repeated stress. I thought about having someone weld it but you never know if they will burn the inner surface of the bowl. I do not know how much food-quality experience local welders have. Maybe CGers have some knowledge of who can weld-repair stressed-out LM chasses, but the cost might not be worth it. I wonder what the cost of tools for placing solid rivets is? I like repairing and crafting things out of metal with tiny, recessed screws, either tapped in or secured with nuts. The thinness of the bowl would require a reinforcing plate to countersink the screwheads, but I think the solid rivet idea sounds promising - except I have no experience. Maybe this will be a good learning opportunity, if the investment is not too high.
Posted Fri Jan 11, 2013, 7:33am Subject: Re: Request for help in handyman project stainless steel adhesive
Dear Troposcuba,
You have intrigued me with the idea of learning to use solid rivets. I can buy a reasonable amount of 1/8" stainless roundheads from Grainger and small (15 lb.), cheap anvils are plentiful. I would be using the artisanal armorer or jewler technique of striking the stem end while supporting the head, rather than use a bucking bar and riveting gun (since the head is in the bowl, can't clear the bowl with the gun). I am thinking about using a rotating wedge strike (back of riveting hammer) rather than a pein strike (edge) and might modify my technique by striking a very small cold chisel in the manner of a riveting hammer head for more precision and clearance. After all, I only have to do this four times (assuming no mistakes!). The one problem that I have run into: in order not to deform the round SS head on the supporting anvil, I want to construct a small supporting cradle to fit between the SS head and the anvil out of some soft material, i.e. copper. I would rough out a .094" hemispheric depression in the copper with a drill or grinder, then mate the rivet head to the depression by securing a spare rivet stem in a drill and mating the head into the depression with grinding compound, leaving the depression shallow enough or subsequently beveling the edges of the copper to clear the curvature of the bowl. Trouble is, I can't find the smallest (1/8" x 1/2" would do) piece of copper scrap anywhere in this godforsaken city..and I am not going to spend $10 to buy and ship a tiny piece of copper scrap from online. All of the small jobber scrapyards have disappeared in this area only to be replaced by large dealers who do not want to have anything to do with 'the public'. When I find something I will proceed.
calblacksmith Moderator Joined: 25 Nov 2007 Posts: 5,685 Location: Riverside, Ca, U.S.A. Expertise: I live coffee
Espresso: ECM Veneziano A1 Grinder: Many different commercial Vac Pot: 40s era Silex Drip: Milita, Bunn&Curtis... Roaster: Cast iron pan, gas burner
Posted Wed Jan 16, 2013, 7:49am Subject: Re: Request for help in handyman project stainless steel adhesive
Don't bother with a cheep anvil, you don't need it and it is not a good tool, only good for use as a door stop and not a very good one of those.
If you have a bench vise, just get a chunk of scrap steel, perhaps a chunk of round stock, drill a depression the size of the rivet head you want to use, clamp it in the vise and rivet your rivet. A ball pien hammer is all you need. I have set a lot of rivets through the years and I know the difference between a good anvil and a poor ASO (anvil shaped object) My handle is more than just a name, it is an occupation. Broken into two words, Cal (short for California) Blacksmith.
In real life, my name is Wayne P.
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