Expanding foam...

[Neodogg]

I was think...over time boards will sag in the middle from age and can ruin a good pcb. What if you’d put some of the expandable foam underneath to give it support. The door and window stuff expands a little but not enough to throw stuff out of square. I’d assume that would be the best option? Would the stuff short circuit the board? Thoughts and ideas welcome...

 

[wyo]

I was think...over time boards will sag in the middle from age and can ruin a good pcb. What if you’d put some of the expandable foam underneath to give it support. The door and window stuff expands a little but not enough to throw stuff out of square. I’d assume that would be the best option? Would the stuff short circuit the board? Thoughts and ideas welcome...

Store boards flat (no feet) in a foam antistatic box or vertically in a cab.

 

[MidnightMonkey]

Store boards flat (no feet) in a foam antistatic box or vertically in a cab.

I mean that works, but what if there's already board sag? As best I can recall polyurethane foam is actually a very good insulator. I'm sure as long as the board isn't already suffering from trace or solder issues that it wouldn't cause any electrical issues. Still, not sure if it's expansion is strong enough to force a board back to square. It would probably expand in the direction of least resistance.

 

[MCF 76]

I don't know if it would be safe for pcb but I know from lots of use it is strong enough to bow doors. I had to cut down several interior door on house we are remodeling and use at bottom because I cut past thin wood bottom sheet. I accidentally put a bit to much and it bowed the door pretty bad. Even thought it could expand outward it still put a huge bow in door. If it is safe to use I would squirt just a small drop in middle & keep a close eye on it until fully expanded.

 

[thegreathopper]

Expanding foam is a nightmare to remove, it would make any repairs hard work. How about the spacers (Pillars) like you get on a 6 slot board.

They come in various sizes, I have used them as supports on pcb’s .. just be careful drilling any new holes

 

[Karou]

Would this not lead to corrosion in humid zones?? I was thinking you could line with something like plastic bags so as not to foam stuff directly...but yeah rust and bad touch?

 

[titchgamer]

I defo would not use expanding foam anywhere near a PCB.

For one that stuff sticks to everything and is a total bastard to remove but also it may actually have the opposite effect.

If you cant store your PCBs totally flat (which takes up lots of room) Store them vertically on their edge which is what I do with mine.
I store them in a plastic tub, just put pieces of stiff card between each board to keep it in place and upright.

 

[ForeverSublime]

Not sure I understand, but it sounds like it'd make the boards run hot.

 

[Bratwurst]

Expanding foam has toluene and other nasty chemicals in it which you don't want to leave on PCBs for the most part, would be best to just use rubber feet or washers in strategic places.

 

[ahcmetal]

Definitely don't spray expanding foam on to the pcb. This Konami board was sagging badly when I originally bought it. Pick up a sheet of plexi glass or wood and mount the pcb to the board with some nuts/bolts and plastic spacers. Slowly tightening the board down will pull the board back into square and support it from sagging in the future. I've done this dozens of times and I've never had a trace break straightening old boards out.