Maserati Biturbo - more pictures

More about the Biturbo

We have repaired a major amount of rust. When faced with extensive corrosion a good approach is to obtain a donor car. Rather than fabricating complicated panels and structural assemblies from scratch, it is almost always easier and less expensive to obtain used parts from another vehicle. Granted this is not always possible but in the case of our Biturbo we found a rust-free car that was being parted-out. We specified where to make the cuts so that we had plenty of material to work with. In this way we were able to replace large portions of the floor pan and adjoining rocker/sill assembly in complete sections.

The first step is to get the undercoating and seam sealer out of the way. Scrapers and propane torches work well but a great (although pricey) tool I like is the rotary wire brush available from several manufacturers. The hook shaped wire bristles are very aggressive (and re-sharpenable). I prefer to clean more than what might seem needed. Later on, during the welding and hammering stage, I have less smoke and drippy undercoating to deal with. Once the pieces are cleaned up we went ahead planning our splices.

We used existing bends, especially in the floor pans to help plan the cut lines. Also, we took advantage of the structure to help make the job easier. So instead of cutting the floor pan just anywhere, we spliced right over an existing stiffener. This gave us a readily identifiable place to cut as well as resulting in a stronger seam.

As you can see, we replaced a large section of the left side floor pan and inner rocker. ‘How did this much damage occur?’ you may be wondering. It seems to us that a few small rust holes opened up high on the firewall. This allowed water to run inside the car which was combined with a long period of outside storage (never a good idea). And of course ‘rust never sleeps’. Quietly doing its job 24/7, happily providing work for those of us foolish enough to go into the auto restoration business. That and, of course the fact that the car was built by the Italians. It must not rain in Italy.

After the welding and grinding were done we applied two-part urethane seam sealer liberally. I’ll back-up here and mention that inside surfaces were painted with either rust encapsulator or zinc-rich weld thru primer prior to welding. We anticipate a tough life for this car so the floor pans and inner sills got two coats of ‘Rustoleum’ enamel. Not historically correct but then this is not to be a museum piece.

The bottoms sections of all fours doors were re-skinned. In addition, I had to fabricate the bottoms of the door frames. Is there polyester filler (bondo) on these doors? Yes. Modern fillers mixed in the correct proportions and applied and used properly, that is, among other things; nothing thicker than 1/8 inch and never forming an edge, will last practically forever. Metal finishing a panel to near perfection takes a lot of time, time that may not be warranted.

After all the body work is flat and sanded with 180 grit, the car gets washed with wax/grease remover followed by a coat of self-etching primer and three coats of surfacer. That’s where we are now. The car has been allowed to dry for over a week so the next step is dry blocking the surfacer with 220 grit on the longest sanding boards practical

Ferrari Daytona

Refinishing the cowl panel on a Ferrari Daytona

The cowl panel on this car detracts from an otherwise clean vehicle. The area between the windshield and the engine bay has suffered several amateur spray can touch-ups and looks rather shabby.

After removing the windshield wipers and washer nozzles I applied masking tape to protect the brightwork around the windshield and also the painted surfaces of the fenders. I definitely do not want to be painting body color or trying to buff sand scratches out of the trim.

The older Italian cars often have some kind of seam sealer applied to fill the gap between windshield moldings and the adjacent body panels. I needed to carefully cut and scrape to remove what appeared to be black silicone. Now I’m ready to start sanding but first I cleaned the whole area with wax and grease remover. That done, I sanded off several layers of flat black paint. The area was too small to use air-powered sanders so I just worked by hand. Starting with 100 grit and finishing with 220, I ended up removing almost all the existing paint and primer. I should mention that I dry-sanded in an effort to reduce the potential for making a mess in an otherwise tidy engine compartment.

Satisfied that I had a good surface to accept primer, I chemically cleaned the area again before masking-off the engine bay, fenders and windshield. The whole car has to be covered to prevent overspray. (Not like in the bad-old days of lacquer primer, that stuff was practically dry as soon as it came out of the gun.)

After a third cleaning, I applied two coats of high-build primer/surfacer. Tomorrow I’ll sand the primer and prepare for paint.

Murcielago exhaust

Back in 2005 when this car came in, all Murcielagos were under warranty. As an indepent shop, we were happy to install Hamann wing and spoiler, upgraded Quicksilver stainless steel exhaust and an ECU upgrade which necessitated using LaRA-AS factory software to ensure the engine and all sensors were performing correctly.

Lamborghini 400GT 2+2

Hard start problems on a Lamborghini 400GT 2+2

This is a pretty car that is in great condition and doesn’t need any body or paint work. I just think it’s got a striking look. As far as I’m concerned Lamborghini styling never got better than this.

This car is in the shop because of hard starting problems. The tech on this job performed an inspection and compression check and, given the good compression numbers, feels the car should perform better than it does. The older cars, more often than not, have problems with carburetor and distributor adjustments. After all, many technicians (previously known as mechanics) have never had to adjust a carburetor and have never even seen a set of ignition points. What the heck is dwell angle?

We will probably do a complete tune-up, set valve lash, adjust cam timing, put the distributors on the machine to make sure the advance curves are correct and adjust the carbs or possibly rebuild them.

Rust

Here we are repairing some fairly extensive rust on a Maserati Biturbo as part of an overall restoration. The bottoms of all four doors need to be patched. This includes the inner doors as well as the outer skins.

I rough-cut the rotted areas to get an idea of how big the patch panel will need to be. Cut a piece of sheet metal a little oversize and fabricate the required features. These particular doors have a simple shape to the bottom of the inner structure and only need the pinchweld flange bent to the proper angle.

Somewhere in here the dirty work has to get done. I’ll clean the insides of the door with scrapers, wax and grease remover or lacquer thinner to remove all traces of sound deadener, undercoating, body wax, whatever, because that’s just the way it has to be.

I will install the doors several times during the process to test the fit of the outer skins before trimming the patch panels to their final dimensions. Whenever possible I like to lay the oversize patch panel over the area and then cut the panel and the original sheet metal to size in one step. I find cutting a straight line with a cut-off tool really hard to do so this is where a good plasma cutter pays for itself in saved time and reduced aggravation.

The patch panel and the original metal need to align without significant force having to be applied. The price of a poorly fitted panel is warpage and distortion which will need to be straightened later on. I always have to remind myself not to take shortcuts at this stage.

And now, onto the welding; I learned the art of hammer welding many years ago and am constantly amazed at how well the technique works. Of course the method was developed when automotive sheet metal was considerably thicker and access to the backside of panels was considerably better but is still to my way of thinking the best way to join two pieces of sheet metal. I also really like the whole oxy-acethelyne ‘thing’. The flame, the sparks, the occasional 2nd or 3rd degree burn. It’s just so macho in a way that TIG will never be.

So, once the welding is done all the slag and oxidation have to be removed. I use the usual assortment of wire brushes followed by a good scrubbing (inside and out) with chemical rust remover. This stuff will remove the last of the welding residue and provide a phosphate coating to protect the surface from rust.

After all that I’ll move to the good old hammer and dolly/pick and file stage to finish the repair.

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From Exoticars USA, in Frenchtown, NJ: restoration of exotic cars - , Italian and English exotics sportcars including: Ferrari, Lamborghini, Maserati, Aston Martin, Cobra. We promise some pretty interesting images of extraordinary cars undergoing transformation. Blogging by Randy Tartanian, blog maintenance by Sandy de Groot.