I was watching Steve Thomas on Renovation Nation and he was covering a SIP build. The builder was discussing electrical chases and how they put in a new chase on site. Basicall they said to take a 1" ball bearing and heat the crap out of it with a torch. Drop it on the foam of a panel on its' end and the bearing will cauterize and melt an almost perfect hole the length of the panel. They showed a SIP only about 3' tall and it took maybe 45 seconds for the bearing to fall out the bottom. They said it can take 3-4 minutes for a wall sized panel. Just curious if anyone has done this. Ian.

Nope. Obviously, you would be sure not to use this builder for any finish work.

I saw it too and thought it was pretty slick. Have not done it.

What happens if the ball isn't hot enough to go all the way through?

I seem to recall seeing this technique shown on a video on Youtube. That was the first question that came into mind. Assuming the ball does not stick to the foam I assume a strong magnet on a cord could be used to extract it. My question is, how can you be sure the hole will be centered in the panel? Too close to the skin and wiring may be damaged by nails/etc.

We did this and it worked great. It was several years ago and I think it was a smaller size of bearing. A flashlight showed a straight chase.

It works like a champ! I use 3/4" stainless steel ball bearings from McMasterCarr.com. Heat it to red hot. Use a piece of metal flashing or metal roof scrap to make a "U" shaped catch can. Place it in the pocket at receptacle height where the ball will fall into. This stops it from continuing on and landing on the sill plate and possibly causing a fire. I've used this technique on 12' walls for ceiling fan wiring from the roof. Heated good and RED hot the ball will go 8 feet for sure. Not so hot and the ball gets lost. Just drop another in the same hole and it goes right around the one that petered out. Gravity brings it straight down.

I have used it myself. As previous posters have written, you do need to ensure that you keep a flame to the ball bearing for some time before dropping it through a panel. A more consistent method is using a piece of all-thread with the appropriate sized washer (and a level to make sure the chase is level and true) with the appropriate heat source. This ensures nothing to get stuck in a panel.

Joe Quinn
Enercept Building Systems
(800) 658-3303
[email protected]

I had a friend report viewing an Insulspan installer trying this and almost burned down the work. It's easy to get the steel ball hotter than the flash point of EPS. If attemped, you need to instantly close off the hole to block air, and you'd better have water and/or a fire extingusher handy. My opinion - it's better to use standard techniques such as drilling holes and use a flexable drill bit. Roe Sun Styles Timber Framing 804-378-0501

My SIP supplier says it works. As a Fire Fighter, I'm not going to try it any time soon.

Everyone should keep a fire extinguisher as part of the tool trailer, or in the truck. Ya never know...