Modar Body Parts Carplast / Stratime

Because of the limited production numbers from the SZ / RZ and some more reasons, Alfa Romeo decided not to use traditional sheet metal for the cars "skin" but a composite material instead. Most of the SZ / RZ body parts have been made from a composite material called MODAR. Over the steel structure from the SZ / RZ this modar and glisfibre "skin" was glued.

Piatti wrote this about it in his SZ book:

"Of the three materials choosen to clothe the steel structure of the Alfa Romeo coupe, two are composites in glass-fibre and carbon-fibre. The other is aluminium, chosen for the roof panel. Apart from the well known qualities of carbon, also used for the rear wing material, formed by cold injection moulding the Thermosetting Metacrylic Resin, known as MODAR, together with glass fibre also possesses some very interesting characteristics and in fact this was the composite to clothe most of the SZ.
Alfa Romeo already used MODAR for the bumpers on the Spider, but on that occasion the material was compression moulded. The SZ on the other hand, the injection moulding technique was preferred in order to resolve problems involving surface finishing, the uniformity of thickness and air absorption on far larger panels.
Modar resin, produced by I.C.I is noted for his high impact resistance and ease of working while it also unites the possibility of obtaining even more robust composites with qualities like high flame resistance and low smoke emission as well as excellent surface finish and improved productivity.
Modar has registered figures for shock resistance and elongation at break, wich are superior to those for polyester. The impact strenght of polyester varies from 5-15 kj/m2 while that of Modar is 30 kj/m2. Polyester will elongate from 1.5-3% before breaking, while modar will stretch as good as 6.5% before snapping.
As well as posessing good moulding qualities, Modar is also immune to the assault of atmospheric agents. Furthermore paint clings on to it extremely well,..... "

Than some remarks from me personally:

1.) The book from Piatti only mentions the company "Car Plast" in Italy who made those modar panels,....but un-mentioned is that also the company "Stratime" in France made those panels for the SZ. It is a company specialized in all kind of "plastic / polyester ecc.ecc" products and it still does exist. In the back of the picture ( taken from their folder ) you can see some SZ hoods been lined up.

Stratime:

Carplast:

If you like to see a larger picture, click the thumbnail.

2.) Modar seems to be a good material, but in the end those Modar panels used on the SZ / RZ are often heavier than if they would have been made as normal steel panels.
3.) About finishing the panels and "paint clings on it extremely well".... we all know how the paint on most SZ - RZ's has been finished and the problem of the micro blisters also appeared on almost every car.
4.) I am not sure that the break qualities from modar are much superior to - modern - polyester. We had some moulds made from original never been used SZ panels. It was not hard to had a piece braken off the original modar panels because it seems harder than polyester, but polyester was more flexible and seems to have longer fibres... maybe it de-formes a bit easier, but it will not break so easy, certainly not if used in the same thickness as the original modar panels are.
5.) Than the part of: "the uniformity of thickness".... everyone who for instance, took off a front or rear bumper, knows that there is not so much "uniformity of thickness" if you look at the back side of those parts

If your car looks like this.........