SMC Discussion Areas

I am having a condensation & rust issue with a set of original doors on my Westy Master cooler. When I got the doors (like most) they had some rust but only just a few little pin holes here and there noting big. After a little body work and paint they looked great. I used the cooler a few times when I started to notice a couple of small water bubbles appearing under the paint.  :darn:  So I can only assume condensation is building up inside the lid. I fear the inside of the lids will continue to rust from the inside out unless addressed.

So what is the best way to tackle this and still keep the embossing?

Is it possible to just cut out the sheet metal on the top, pull the old insulation out, treat the rust and seal the inside surface then re-weld the top then fill with expansion foam? 

      I'm thinkin' you maybe didn't kill all the old rust before filling and painting.
You may be able to just sandblast the bad area and spray the remaining metal with a rust treatment solution and repaint.

I am thinking your right. Its almost impossible to get inside the lid without cutting it open. So I think that's what I need to do, kill & seal it from both sides. That insulation mat is like a sponge so that isn't helping the issue.

some pre-war chests used wood in the lids, which contributed to the rust-out by creating tanic acids that ate at the metal from the inside out, ( same problem as on a Vendo V110 's bottle door) one way to tell if you have fiberglass or wood filler is to take a thin brazing rod or such ( coat-hanger wire would do too) & try to poke through to the opposite side of the lid, if the wire sinks the depth of the metal lids, it's fiberglass, if you meet with resistance, it's wood. plus the metal gauge itself is pretty thin & they went ahead & embossed it , thus stretchering the metal even thinner along the rise an crest of the embossing, this is were most rust out starts on these lids, you have to tear them open to kill the rust on the inside I'm afraid no mater what the insulation used..PS wood insulated lids also weigh quite a bit more than 'glass filled ones.


Foam insulation may present a problem with bowing (swelling)the lids as it expands, so I'd use a low expansion type if that's the way you are going.

They were made in 1937 so I would venture to say I have the wood as they are extremely heavy for their size and met allot of resistance shoving a coat hanger into it. It sounds like cutting them open is about the only option to get them sealed up properly. I was leaning toward using the expanding foam because I was afraid anything else would possible catch fire during the welding process. that way I could weld them up then apply the spray foam through one of the hinge screw holes. I didn't think about the foam expanding causing the surface to bow so I will insure I use the low expanding type.  

Yep, one of the spots is on the embossing. I didn't see it when I worked them over the first time.  Do you recomend going in through the top or bottom embossed side?