Glue gun vs JB weld vs Epoxy on alu cases....which is best?

[momo]

Im having problems glueing a piece of metal to the back of a pot....holds ok but it snaps off if hit. Also would like to glue that metal piece to the case. I would like to know your opinions, I don't want to buy stuff that does a half-a$$ job!
Did a search, but its mostly individual comments on one type, anyone use all 3 and know which is best?

[5thumbs]

I didn't have stellar results with JB Weld/JB Kwik/"5-minute Auto Epoxy" until I roughed up both surfaces I wanted to adhere.  I started roughing up the surfaces w/60-grit sandpaper using a tight circular pattern, then cleaned them with naptha or acetone afterwards.  I've not had problems getting them to stick after that.

I've never tried hot glue for this particular application, but roughing up the surfaces would probably improve its chances of sticking as well.

Good luck!

[petemoore]

  Aluminum contracts faster and more than steel, especially when it's the one out in the cold holding the steel's warmth in it.
  two substrates ' ll ' tend to break anything stiff between them by exerting massive forces when one cools faster than the other, or one contracts more than the other when cooled..YMMV. Peeling is always a possibility.
  JB Weld...good stuff [I can't elaborate on testings comparing it to it's competition], we glued an engine block crack to sealed condition; between 20 below to the engines normal operating condition...yupp...pretty good stuff !
  I use short, self tapping screws for brackets.

[MarcoMike]

I don't know about JB Weld, never heard of it and I wouldn't trust hot glue for "structural" purposes.

I had experience with epoxy on alum (I filled few holes of a box) and I was surprised of the result, very tight!! after painting I couldn't tell the difference. I would trust it for your kind of joint. I used a Buheler bicomponent glue we had in my lab, not sure you can find it around..

[John Lyons]

I didn't have stellar results with JB Weld/JB Kwik/"5-minute Auto Epoxy" until I roughed up both surfaces I wanted to adhere.  I started roughing up the surfaces w/60-grit sandpaper using a tight circular pattern, then cleaned them with naptha or acetone afterwards.  I've not had problems getting them to stick after that.

I've never tried hot glue for this particular application, but roughing up the surfaces would probably improve its chances of sticking as well.

Good luck!

+1 on cleaning/degreasing and roughing up with a file or sand paper. More surface area to grip the glue.
yes, Heat up the enclosure or anything you want to bond with a hot glue gun. Otherwise the glue cools and does not bond well.
You can also heat it up once it's applied with a hair dryer or heat gun.
Epoxy or JB weld are both better than Hot glue gun for a strong hold. Glue gun is fine of lighter duty holding.

John

[rikkards]

The last pedal I made and the next two I am working on is going to have Gorilla Glue (http://www.gorillaglue.com/)  holding in the Battery Holder as well as the stands for the PCB.

I shall see how well it works over the next while. I ended up buying Weldbond (http://www.weldbondusa.com/) thinking that it may be good and it was mediocre, really liquidy and didn't hold the battery holder. But to give it credit, I didn't sand before using it. I have had success with a Lepage product (yellow transparent glue) but it dried up pretty fast in the bottle. Gorilla Glue looks to be really similar to the Lepage stuff but so far doesn't look to dry as fast in the bottle.

[John Lyons]

Lepage is for paper and maybe wood.

Gorilla glue is for wood as well as far as I know.
Lotsa hype, not that great in my opinion. Tightbond II is better for wood, cleaner working/cleanup as well!

john

[birt]

solder it to the pot and screw or rivet it to the enclosure?

[juse]

Doing a thumbnail/guitar pick adjust like the blackstone? Very cool. You could also use a pcb tabbed pot into your board in addition to the bracket, make it all one piece.

[frank_p]

I have a chart here from a boat building book.  I says that in the two components epoxies "Alardite fast" is the one who has the best "bloc strenght" and the best "surface strenhgt".

It's a product from:  Huntsman Advanced Materials

This is their web page:
http://www.huntsman.com/advanced_materials/eng/Home/Adhesives/Araldite%C2%AE_Adhesives/index.cfm?PageID=5865

They make a lot of epoxies for electronic componets casings by the way.
I have not tried myself but the test results are from an independent DIYer.

Hope it helps and if it works, tell us !

Frank

[MikeH]

I've had success doing similar binding with Gorilla Glue.  It will bond pretty much anything, and I don't think it gets quite as rock hard as other things, which allows it to give ever-so-slightly and therefore is less likely to break.

[5thumbs]

I've had success doing similar binding with Gorilla Glue.  It will bond pretty much anything, and I don't think it gets quite as rock hard as other things, which allows it to give ever-so-slightly and therefore is less likely to break.

Mike's got a good point about Gorilla Glue.  GG is good stuff for any job where you can apply clamping pressure and glue overrun can be tolerated or cleaned up with a sharp blade later.  GG is an expanding glue, so you need to keep some positioning pressure on it while it expands and dries.  This expanding characteristic also makes it tend to foam its way out of gaps between the items being glued, so be prepared for that.

GG has worked well for me, but I've fallen back into old habits and switched back to 5-minute epoxy because I'm too busy/impatient/immature/etc. to wait like I should sometimes.

[momo]

Doing a thumbnail/guitar pick adjust like the blackstone? Very cool. You could also use a pcb tabbed pot into your board in addition to the bracket, make it all one piece.

Yes im putting an external bias for a rangemaster, I will try to see if I can use a low profile screw at the bottom of the pot, I don't know if there is enough space in there. If it works, then ill just have to glue the whole setup in the case. Some great info here, ill have to reread and see what ill do. Its frustrating cause if the epoxy would of lasted on the pot, this box would already be in the pictures thread!
Next time though, ill figure out a piece of metal that would be held by another pot that goes on top of the box, that will require no glue and will last forever.(did not think of that when I was searching where to exit the bias pot).

[juse]

Yes im putting an external bias for a rangemaster, I will try to see if I can use a low profile screw at the bottom of the pot, I don't know if there is enough space in there.

How about something like this, getting rid of the glue/jb weld, etc. all together?
Make a bracket and mount it to your board.





Of course you'd have to anchor the board then

[slacker]

What I'd do is make a bracket to hold the pot like Tim has suggested, but make the plate big enough so that it covers that hole in the box with the red spot by it. Once you've got the pot lined up drill through the plate lining the hole up with the hole in the box. Then use the pot or whatever is going in that hole in the box to hold the bracket in place.

[momo]

Wow Juse, did you do that custom for the tread? , nice graphics, I will anchor the board, that seems doable for me!
Im not home for the weekend so ill have to check that Monday. thanks for the visuals!

[juse]

Wow Juse, did you do that custom for the tread? ,

Yeah, I did it when I was supposed to be working..... 

Seems doable, I've been wanting to try it myself, so this gave me an opportunity to think about it. I like the idea of setting the controls & not worrying about if it gets bumped & turned somehow - at least for a pedal like an od where I don't change it anyway after it is set.

[frank_p]

Juse. How do you enter in sonicmojo.com ?

[frank_p]

  Comming soon OK

[juse]

Comming soon OK

Yeah, sorry - it's down right now. It'll be awhile before it's up & going.