MG Sports Cars

This properly belongs over in the body area but I'm posting here as it is more frequently visited. For those who have been following my build - [forum.britishv8.org] - this is the promised "How To" on the speedster door from my last installment. To those who are great at bodywork, you may want to avert your eyes. I use simple tools that work for me and am entirely self-taught.

There's a shot of the roughed in driver's door at the bottom of the page so folks will know what we're shootin' for. For those of you who want to know "why" speedster doors, I refer you to the embedded thread for the answer.

Caveat: this is not an easily reversible modification. So, if you think it's something you'd like to do, think twice before you embark on it. It's not a difficult change, but it's pretty permanent.

Start with a completely stripped door. I find that my shopmate makes a great tool to help support the door while I work on it and easily adapts to a variety of positions so I can have the work in the most ideal place for the task at hand. Once you have the all of the hardware removed, use a grinder with a 60 grit flap wheel to remove all of the paint (and, in this case, some previous and poorly done bodywork) from both the inside of and outside of the top of the door. You'll need to remove about 4-5" on the outside and about 2-3" on the inside. Why not just blast the whole door you ask? Because, in my case this isn't going to be a show car and will likely see quite a bit of track time so it doesn't make any sense to go nuts with the finish quality. After you've cut back the cap area, go ahead and sand off the rest of the door. I used a simple palm sander (orbital type) with 80 grit paper and feathered the remaining paint/primer into the repair area.

Here's what the prepped door looks like, including the dreaded "crack of doom" and really crummy repair made by some previous owner.



It's not necessary to go crazy fixing old bodywork but the surfaces where the door and cap meet should fit tight and be free of old filler (down to the metal) so the panel adhesive has a good gripping surface. I used my slide hammer, a spoon dolly and a some careful tapping with a body hammer to bring the old repair back to a more respectable state. For the truly detail crazy, you could carefully weld the crack together then grind it down but it's not really necessary.

Next thing to do is to remove the lip on the inside of the door so the cap can fit snug to the door. I did this using a saber saw (metal blade) to remove the bulk of the lip and a 60 grit flap wheel to dress the edge.



Then, it's on to forming the new door cap. I use 22 gauge mild steel for this. Once it's formed into the cap with the sharp crease, it's more than strong enough for this application and is easy to work into a smooth contour. You'll need a piece 3" x 32" for each cap, marked 1" down the long side (see pic) so you know where to make the first bend. I don't have any fancy forming tools so this was done using: a couple pieces of 2" angle iron, "c" clamps, my bench vise, a body hammer, and a tow dolly. Carefully to clamp the metal strip between the two pieces of angle iron making sure you keep the 1" line just visible at the top edge of the irons. Clamp on both ends and drop the whole business in the bench vise (about in the middle). I start the forming by hand, then finish it with a flat body hammer to get a nice crisp edge. Take some extra time once you've made the initial bend to tap out any waves. This gauge of steel is very malleable and will warp easily until you have a stable shape.

The angle of the cap needs to be more than 90º. I accomplished it by simply placing the 1" side on a flat surface and use my hands to create the acute angle (I took the piece back to my bench vise and used the tail to hammer the edges flat again). I checked the angle once again against the door. Once I'm happy that the initial angle is correct, it's back to the bench vise to form the curve. To do this, I clamped a toe dolly into my vise and bent the 2" side of the steel to its contour (which just happened to be almost exactly what is needed). Take your time and so you don't create more work for yourself later. I'll post some shots of the formed cap and the dolly procedure in the next installment.



Okay, I don't mean to be a tease, but I'm out of room for pictures here so you can see how the rough cap looks by visiting my build thread. In Part II, I'll install the cap using metal-to-metal auto body adhesive, blending it in to the door, and finishing it off with plastic filler.



Edited 4 time(s). Last edit at 08/29/2011 11:50AM by DC Townsend.

Keep 'em coming, looks good.

This is going to be awesome when finished. Betcha didn't now the Workmate was a product of Lotus design: [www.dailymail.co.uk]

"when finished"

The critical phrase...but it's getting closer and I finally have more parts on the beast than I do in boxes. I think that's a good sign.

Rick, you are one knowledgeable dude. I did NOT know that the work mate was a Lotus Design piece. But I do now, am armed and dangerous, and set to wow my friends.

DT

You've reached what I refer to as the critical phrase of a project, "When the unbolting ends and the bolting begins."

Here's a shot of the forming tools for the cap. Simple stuff - a dolly, a vise, and a body hammer. It takes a little practice to be able to do this with the right result but it's not hard to learn.

Here's a shot of the finished cap. After clamping the cap to the door, I very carefully tap out any small waves to get it to fit as flush as possible to the surface (prior to installation). You need to go slow and use very light pressure when you're finishing the cap to the door so you don't warp either it or the door. The area around the two access holes on the inside (front) will be tapped in to conform to the contour before the cap is installed.

Here's a shot showing the cap contour and some of the fine tuning. You can see how closely the curves need to match as well as the angle of the bend.



It's important that everything fit as snug as possible both to minimize the need for fillers as well as to ensure a strong bond with the adhesive. This next shot shows the countersunk holes for the rivets that will help keep the inside of the cap tight to the door. On the outside, I can clamp it down using a piece of square tubing and a few c-clamps. But there's no way to get a good purchase with clamps for the inside so I rivet the cap here (countersunk, 1/8" steel rivets) then dress the work with a flap wheel after the adhesive dries.



Before I lay the adhesive down, I use a felt marker to trace the contour of the cap on the door. The first bead of of adhesive is laid on the inside of the door just inside the trace line, the second bead goes down for the outside but I lay it on the cap instead of the door. This allows me to more easily position everything before I clamp and rivet into place. This adhesive has about a 60 minute working time so you don't need to be in a hurry. The stuff is incredibly strong so you need to get it right the first time as it is nearly impossible to peel the cap off and start over. Meant to take a picture of the adhesive going down but flat out forgot to pick up the camera as I was busy getting things secured.

This shot shows the complete cap after the adhesive has cured (about 24 hours). Before applying any filler, I first hit the area with an 80 grit flap wheel to bevel the remaining edge of the cap where it meets the original door and to create a good grip for the filler. I also take a little time to carefully file the corners to make sure the transitions there are smooth and free of any burrs. Then clean the area thoroughly with a degreaser like Prepsol or PPG 900.



I like All-Metal for this application as it has 0% shrinkage and provides a nice metal-to-metal base for the final filler coat(s). I've also used 3M HSRF for applications like this. Both fillers have excellent adhesive properties. The camera lighting is making my application look worse than it really was but you want to work fairly quickly. You don't need to get crazy trying to make the contour perfect, we'll take care of that with plastic filler. After the All-Metal has cured, I use a long board with 36 grit to knock down the high spots and to give the next filler a good grip surface.



When you're knocking down the All-Metal (actually, this applies to all of the filler applications), you want to sand diagonally - in both directions - rather than down the length of the door. This will help ensure you don't sand in any flat spots or ridges.

Next post will show the door with the finish filler, primed, and ready to install.

Here's the door with two coats of filler on it. I use a product called Feather-Rite (rather than Rage or similar) for this because it can be used on metal, over primer, over old bodywork, etc. I didn't want to strip my doors down to the metal so there was bound to be some filler overlap on to old paint areas. As long as they've been scuffed with 80 grit, Feather-Rite will adhere quite well.

The best way to spread the filler (at least for me) was to use a 3M rubber squeegee rather than the harder plastic ones you would typically use. Mix your filler according to the instructions of the product you use. How much you will need will depend on how close the fits and contour of your cap is but the application process should go something like this: moving from top to bottom, left to right spread a layer of filler over the length of the repair (mine came down about 4-5" on the door), carefully clean any built up filler from your squeegee, then bend your squeegee as close to the contour of the door as you can get and, starting at whichever end you prefer, drag it lengthwise down the door. Don't use too much pressure (you're not trying to squeeze out the filler, just create nice contour) here. Clean up the small ridges at the top and bottom of your pull and your first pass is done. I've worked with this particular product for quite a while and know it's mixing and drying properties fairly well so I was also able to put a coat of filler on both the outside and inside of the cap as well as a pass over the holes where the trim strip used to be.




Before I prime the door, I'll go over it with 150 grit and clean up any grease or oil from the hinges and any other places I may have missed earlier. Because this is going to be mostly a track-day car, I'm not going crazy about finish quality so for this step I just use a urethane-base rattle can primer. Later, when the car goes to paint, I'll sand down the entire surface and shoot the whole thing with Featherfill before it gets final finish.

Here's the primed door after it was sanded with 150 grit paper, wiped down with de-greaser, and had a tack cloth run over it. After the first coat dried, I sprayed some guide coat (Eastwood Company) on it then carefully sanded with 220 grit and shot a second coat (there weren't any spots so low that they won't level out when I shoot the Featherfill prior to finish paint). At this point, I'll let the primer get good and dry, lightly sand with 320 grit, then spray the perimeter and inside color (including the hinges).

Before the door is ready to install, the inside needs to be sprayed with Eastwood Company's rust inhibitor, then sealed to prevent any more moisture from migrating through the finish and attacking the metal. Lastly, I'll install some sound deadening that will help take away some of the tinniness caused by removing all of the door glass and related window parts.

After I finish painting the jambs and sill on the passenger side, the door will be ready to hang.




That's all for Part I of the Speedster Door - How To. In Part II, I'll be shooting color on the perimeter of the door, modifying and installing the latches, installing the blanking plug for the door lock holes, and starting the inside door panel which, in this case, is going to be a simple piece of T6061 screwed to the door. This may not seem like much for part II but I can tell from having gone through it on the driver's door, there's more to it then may seem.



Edited 1 time(s). Last edit at 09/05/2011 03:36PM by DC Townsend.