[tangent]

What is the yellowish white glue you see used to secure large electrolytic caps to circuit boards?

 

[eric343]

Hot glue?

 

[tangent]

Yes, that's true, I've seen that. The stuff I'm thinking of is less transparent, though, kind of like wood glue. I suspect it's popular because it's flexible but not gummy, so it doesn't crack in normal use but you can still remove the caps if you want.

 

[Voodoochile]

There is a woodworker's glue called Gorilla Glue that sounds similar in appearance, and does retain some flexibility after curing. Woodcraft carries it... probably many other suppliers as well.

But I don't know how well it behaves on non-porous surfaces. It can actually bond green and oily wood though, which is remarkable.

Maybe check into a short-run manufacturing house that does circuit boards and see if they will share some info?

 

[winston61]

DON'T use gorilla glue! It is a polyurethane glue that cures with moisture and will foam and spread and destroy your circuit board.
I'll bet it is a 3M product, they make an incredible range of adhesives and a call to them or a visit to a website may hold the answer.

 

[jeffreyj]

Tangent -

eric343's guess was right: it's hot glue. It's used to hold the capacitors (and other parts) in place until they are wave-soldered.

 

[BPRJam]

Quote:

Originally posted by jeffreyj Tangent - eric343's guess was right: it's hot glue. It's used to hold the capacitors (and other parts) in place until they are wave-soldered.

It is hot glue, but it is a different grade than the clear hobby glue that you generally find. I'm not 100% sure, but I think that it is meant to hold very non-porous items together, whereas the other stuff tends to peel off non-porous surfaces fairly easily.

Once upon a time I got some from Hobby Lobby, but I haven't seen sticks of it in years. The sticks of it were yellow, like the "wood glue" color Tangent was describing.

BPRJam

 

[Voodoochile]

Quote:

Originally posted by winston61 DON'T use gorilla glue! It is a polyurethane glue that cures with moisture and will foam and spread and destroy your circuit board.

Good to know! How did you find out about the PCB repercussions, anyway?


I've only used hot melt myself, but it does not seem to be the same as the stuff that commercial houses use. Perhaps their's is a hi-temp variety.

 

[AndrewB]

Tangent,

White/Clear RTV works well. Loctite makes a variety of RTV's , They're available everywhere.(Walmart, McPart's, Kmart...)[size=xx-small]RTV= room temperature vulcanizing..............for those that gotta know[/size]

 

[winston61]

Try this link, it may be start for what you need.


http://www.3m.com/us/mfg_industrial/adhesives/easd/

 

[Voodoochile]

Sure enough... Jetmelt

 

[jeffreyj]

Quote:

Originally posted by Voodoochile Sure enough... Jetmelt

Good sleuthing work!

Wonder how much this special hot-melt glue costs, though??

 

[Voodoochile]

That link was simply a deeper dig on winston's linky. Credit where credit is due!

I suppose we should always guess 3M when looking for sticky or abrasive stuff. As for quantities, Mouser or Digikey might be able to get small quantities, as they carry other 3M products. The hotmelt available locally to me is not nearly as tacky, and will pop off fairly easily, even with good washing of the board with alcohol.