Bodywork and Glass Insulation

Insulation - General - Covkid

Beat The Winter Freeze And Insulate Your Van

For those like myself that migrated from Beetles and Type 2's, the lack of insulation in T25s (noticeably panel vans) comes as no surprise whatsoever. VW tended to keep things relatively simple, with models ranging from the basic shell to what the company described as 'luxury' - usually meaning an extra bit of trim or padding here and there, but most of them lacked adequate insulation. On aircooled vehicles this could really show itself during the winter and even on a watercooled, a great deal of heat is lost through the body. My thanks to 'Samk' and other for additional images and input.

With many conversions, you may well find the vehicle already has some degree of insulation, but even where insulation has been fitted, its worth having a look to see what materials were used and whether you can improve things. It shouldn't cost much more than £40 - £50 maximum.

You could throw a great deal of money at this including sound-deadening panels (see 'links external' further down this page), but you can do much to retain heat and reduce noise relatively cheaply and without a great deal of work. Firstly, by far the most useful material is the alumninium-faced bubble wrap available in big DIY stores. For one thing it doesn't soak up moisture, and tends to reflect heat back. As an insulation barrier its good stuff, not too thick, reduces noise, and can easily be cut and put under carpets, into door cavities and so forth. If you pick the right week, many shops have two-for-one prices.

Doors & Cab

The front doors are nearly always devoid of any insulation whatsoever - unfortunate since thats the one place you really don't want to be losing heat. You're restricted a little here due to the room needed for the window when its wound down - glass fibre not really an option. However, the Thermal wrap is easily cut to the shape on the door (allowing a couple of inches over at the bottom and sides to wrap round in a loose 'tray' shape. Getting the sheet inside the door requires rolling up the cut sheet, then feeding it through the aperature with the window wound up, unrolling it inside the door (bit of a squeeze) and then taping it in place where suitable. You could if you wished stick sound deadening material or flashband to the outside metal first although the thermal wrap is fairly effective on its own.

The cab floor should be completely covered in thermal wrap as far up the front bulkhead as you can go, and under the front seats. It will fit nicely under mats or carpets. Harrymann's excellent article (further down this page) details specific measures that can be used to further reduce noise below the seats and its well worth doing if its within your budget and you want to be able to hear Debussy on your stereo.

Sliding Door & Opposite Panel

Again, cut and fit thermal roll. Heres your first opportunity to add glass fibre. I strongly recommend that you either use space blanket (glass fibre encased in a sleeve with both ends taped up), or at least put glass fibre in polythene. If you don't, any moisture within these panels (and T25 windows do appear to leak eventually either through poor design or corroded window rubbers), the fibre will act like a sponge. locking in the moisture and leaving you with panels full of wet fluff. If you encase it, any water should run down past the filling and out through the bottom. You may have to reduce the thickness of the glass fibre depending on the depth of the panel in some areas.

Rear Panels

Less opportunity for thermal wrap here but I found that glass fibre tucked into carrier bags (not bio-degradable bags) fitted these cavities fairly well.

Rear Hatch

Again, thermal wrap cut to fit then glass fibre in polythene. Always reseal panels with tough polythene to prevent any internal panel moisture warping trim panels.

Roof & Floor

My roof was already well insulated (Caravelle) but you may find you have the option to line roof and remaining floor with thermal wrap.

Links - 80-90 Wiki

There are some good links here, in the Camping section of Club 80-90 Wiki Camping interior - rust/insulation

Links - external

Particularly the ubiquitous Bulley-Hewlett link on insulating and heating a camper van Bulley-Hewlett article

Front seat box area

HarryMann: Front seat box/battery box ~ Rust-area and sound/heat insulating

The front seat boxes on the T25, directly above the front spring hanger/turret, consist of a simple sheet steel box, with the flat bottom panels having pressed 'fingers' for stiffening. The box steps down to the battery box behind. They have effectively zero heat insulation, and transmit lots of suspension and road-wheel noise, unless heavily undersealed. The flat bottom is hard to get to and don't think is normally undersealed for this reason, nor the forward or inside faces.

After 15~20 years, these boxes can be showing signs of surface rust underneath, or even be perforated. For some reason the off-side seems worse than nearside on the two I've dealt with, which obviously points at the battery, or its connections and earths possibly being a source. If you're dropping your springs and shockers out, this would be a good time to attack the bottom of the seat tray with a wire brush, partic. checking for seam rust at the far back welded lip (the top of the panel by the handbrake from inside). Though this can be done at any time, access slows you up a bit. Thoroughly dry out once any rust has been uncovered (hot air-gun on 'mild' heat), and treat with your fav rust treatment. This one here has also had a quick spray coat of Chassis Black over the top of a thick brushed coat of Rust Encapsulator.

File:N-s seatbox treated chs.jpg

Next up, once that's all done ~ Stopping that drumming, transmitted wheel noise and keeping your botty warm!

A big difference can be made to this thin panel, by insulating from the outside. I used 12mm foil covered cross-linked ethylene foam (super roll-up camping mat, eBay, about £5 for 2m x 0.6m), cutting it accurately to panel shapes, ensuring it goes right up to the edges. HD spray adhesive onto both surfaces, a couple of thin coats, more if you want to wait for each to tack, then the difficult bit, manoeuvering the insulation panel into place without getting it hung up on the glue in the wrong spot. Having allowed for the thickness and butted them against each other nicely, I finished off with ally foil tape (Screwfix), lapping all the egdes as well as I could. Being a Syncro, a lot of shutz will be flying around up there!

NB. I only did the back (inside most)panel, the top and the front, as the rear step down to the battery box was heavily undersealed without any obvious fractures/cavities. Underseal is a double-edged sword. Where it was not applied to a fully dry area, over seams, bolt heads etc cavities often form, and they are a rust hotspot. If you see it flaking at all, there will be much worse behind as moisture will get in and stay there, and welded/flanged seams particularly, suffer (e.g. in inner wing just in front of the front jacking point).

File:N-s seatbox insulation chs.jpg

Finally, I've started on the inside of the seatbox, using self-adhesive bitumastic sound-deadening. Being a skinflint I've just filled the pressed fingers (cannot find a reasonable cost source of this brilliant stuff). The correct way to use it is to warm it up in the oven, or use a heat-gun (gently), and form it across a large area of a panel, in this case right into the pressed shapes. Ideally, a further sound and heat benefit would be had by also then lining this box out with cross-linked foam, also stopping stored stuff rattling about in there. However, the foil covered one would be better from a fire-hazard point-of-view, though is thicker. Whatever you use, it should either be moisture-proof itself or encapsulated using an impervious barrier such as heavily taped thick polythene (see the Bulley-Hewlett link above).

File:N-s seatbox bitumastic chs.jpg