Using JB Weld to mount stand-offs?

[therecordingart]

Have any of you used JB Weld to mount stand-offs inside an aluminum enclosure? I don't want to get creative with hiding screws, and I need this box I'm building to be road worthy because it will be gigged with heavily. I can't help but fear that it'll break or become brittle over time.

[Paul Marossy]

In my experience, JB Weld isn't as tough or durable as claimed. Maybe you have to mix the two parts perfectly or something, I dunno.

Personally, I like to use these things: http://www.smallbearelec.com/Detail.bok?no=76

Once you stick them on, they are ON for good.

[rousejeremy]

I was just at the hardware store and wondering the same thing myself. What does everyone use?

[head_spaz]

I use JB-Weld for standoffs all the time. It cures solid enough that I quit bothering to use screws thru the top.
The key is to mix it VERY thoroughly, and then mix it some more.
I've seen engine blocks and transmission cases "repaired" with JB-Weld... and doing the job quite nicely. Holds up to heat and pressure quite well. I even saw an intake manifold gooped up once... and put to use within a 1/4" of the exhaust manifold, right at the exhaust port... and it's holding up.. going on 15 years now.
I wouldn't go so far as to trust the stuff on my drivetrain... being the anvil bender that I am... but it is remarkable stuff.
Works great with standoffs. (But be sure to scuff the surfaces up a bit first.)

[Paul Marossy]

I use JB-Weld for standoffs all the time. It cures solid enough that I quit bothering to use screws thru the top.
The key is to mix it VERY thoroughly, and then mix it some more.

That must be my problem, I must not mix it enough.

[m-theory]

I've never been able to get JB weld to hold these things.  At some point in my eternal quest to find the magic potion, I somehow found that plastic epoxy works remarkably well, with the added benefit of setting up in minutes, rather than the hours that it takes JB Weld to set. 

[haroldjenkins]

I've used JB Weld with some success on various repairs.

However, I did the exact thing you're talking about with the standoffs inside my Phase 45 box, and it didn't hold very long at all. It may have had something to do with the small footprint of those standoffs, or it may be that I didn't mix it up right, or perhaps it was the fact that both the tubes of stuff were laying outside in the garage for a couple of years. I ended up drilling holes in the bottom of the box and threading screws into the bottom half of the standoffs.

[joegagan]

also worth considering is a one part polyurethane. saves the mix time. a good example of success with this is the way keeley glues his  2nd inductor into his modded crybabies. i physically pulled very hard on the one i had in for repair, the inductor would not budge, i imagine that it would have taken serious force to ever remove it. the secret is to get a large pool of the glue for a large bonding area. finding a glue that i has a solid body when applying so it doesn't run all over the place as you set the piece.

for standoffs, a large glue blob would prob do it.

upside-low cost and no mixing time or possible mixing errors.

downside is a high skill level is required to utilize, and the extra dry time.

i am about to do some experiments with PL brand polyurethane construction adhesive from lowe's home improvement store at 7 bucks for 28 ounces, you could probably glue up 5 thousand standoffs or more for cheap. i have used this glue for years in construction, is is near impossible to remove for all materials i've tried. i had to replace a gate slat due to warpage, i had to shred the wood apart to remove the picket. amazing stuff.

[joegagan]

*note, i do not know for a fact that keeley used one part poly, but that is what it looked like to me.

[SonicVI]

I use 3M double sided acrylic foam tape for all my sticky needs.  It's the gray stuff you can get at auto-parts stores. It's made for holding parts onto cars.  I use it for standoffs and battery holders and they don't come off unless you want them to and even then with some effort.

[joegagan]

i am suspicious of foam products but probably too hard on them since there are many different grades and the science has improved immensely in the last 30 yrs.  

my bias comes from those failures of foam inside the MXR peds from the late 70s. it renders the pedal useless ( until repair) in many cases when it breaks down, which a lot of them did.

so , we do not know what the foam will be like that we use now when someone is using my pedal in 2050, which is less than the lifespan of a 60s bigmuff.

i imagine that 3m stuff will still be fine in 50 years, but i just don't have a way to prove it.

[runmikeyrun]

I also use the sticky white plastic mounts from Small Bear.  I really like them, and for small boards you only need two instead of four.  They stick incredibly well.

I've used JB Weld for all kinds of stuff in the past, most notably repairing a crack in the expansion chamber on my dirt bike.  Exhaust pipes get HOT and that stuff never cracked, melted, smoked, or burned.  If mixed and cured properly I don't know why JB Weld wouldn't hold standoffs.  Just remember- the bigger the glob, the better the job

[joegagan]

and when you mix, use throwaway  stix.

if you rhyme it holds a damn long time.

[Paul Marossy]

I also use the sticky white plastic mounts from Small Bear.  I really like them, and for small boards you only need two instead of four.  They stick incredibly well.

That's what I used when I was building pedals professionally (contract building). Like I said in my post above, when you stick them on, they're ON. You better get it right the first time. 

[Earthscum]

You want bondage? 3M VHB

I used to work for a sign company. I had to pull that stuff off walls. The sign had disintegrated around it, and it don't come off easy at all, even after being exposed, itself, to the elements for 3 years, and holding the sign on for about 7 before. South facing wall, to make it even more impressive.

Key is that Aluminum is VERY porous, and holds a ton of the oils used as release agents during the molding process. J-B Weld soaks these oils up and it breaks it down before it really even cures. If you use, at least, Lacquer thinner to clean the surface, you are gonna get good adhesion. Another thing with J-BW is that you can heat-cure it once it's solidly set. That's why it always lasts so long on automotive applications, as well as you have oil visually present, so you automatically assume that the area needs a good prepping before gettin' to fixin'.

[Paul Marossy]

Key is that Aluminum is VERY porous, and holds a ton of the oils used as release agents during the molding process. J-B Weld soaks these oils up and it breaks it down before it really even cures. If you use, at least, Lacquer thinner to clean the surface, you are gonna get good adhesion. Another thing with J-BW is that you can heat-cure it once it's solidly set. That's why it always lasts so long on automotive applications, as well as you have oil visually present, so you automatically assume that the area needs a good prepping before gettin' to fixin'.

Aha! That must be the key right there. Makes sense now.

[LucifersTrip]

In my experience, JB Weld isn't as tough or durable as claimed. Maybe you have to mix the two parts perfectly or something, I dunno.

Personally, I like to use these things: http://www.smallbearelec.com/Detail.bok?no=76

Once you stick them on, they are ON for good.

are those self-adhesive? does anyone have a good closeup pic of those. I can't see from that pic how large the "posts" are and what holds em once you push it thru the pcb

[Paul Marossy]

In my experience, JB Weld isn't as tough or durable as claimed. Maybe you have to mix the two parts perfectly or something, I dunno.

Personally, I like to use these things: http://www.smallbearelec.com/Detail.bok?no=76

Once you stick them on, they are ON for good.

are those self-adhesive? does anyone have a good closeup pic of those. I can't see from that pic how large the "posts" are and what holds em once you push it thru the pcb

Yes, they are self-adhesive. The posts are about 1/2" tall and there's little plastic wedges built into it so that once you stick your PCB on there, it's got a death grip on it. VERY difficult to get your PCB off those things once you have inserted onto those stand-offs. They're made of a pretty tough plastic, too.

[LucifersTrip]

In my experience, JB Weld isn't as tough or durable as claimed. Maybe you have to mix the two parts perfectly or something, I dunno.

Personally, I like to use these things: http://www.smallbearelec.com/Detail.bok?no=76

Once you stick them on, they are ON for good.

are those self-adhesive? does anyone have a good closeup pic of those. I can't see from that pic how large the "posts" are and what holds em once you push it thru the pcb

Yes, they are self-adhesive. The posts are about 1/2" tall and there's little plastic wedges built into it so that once you stick your PCB on there, it's got a death grip on it. VERY difficult to get your PCB off those things once you have inserted onto those stand-offs. They're made of a pretty tough plastic, too.

thanx much for the info...