How to Build a Custom Windshield Frame!
hKustoms are all about styling—taking an original body, chopping it up, and redesigning it to fit the vision in your head. That is one of the things that makes building cars so much fun: you never know what you are going to see next. When you have an art deco model, such as this 1941 Lincoln Continental, much of the original styling is already beautiful—just a few tweaks here and there to make it yours—but there’s one area that was a major failure: the windshield frame. Unlike the rest of the body, which has bold curves and swoopy lines, the windshield frame is plain and boring. In all honesty, it looks like it belongs on a VW Thing or a Jeep, as opposed to one of the most beautiful art deco production cars.
The reality is that everything above the door line is wrong on this car: the windshield and convertible top. The top is being changed out for a handbuilt Carson-style top, but what about that windshield frame? It’s far too flat and square to be left as is. We could try to modify the cast-iron frame, but it would still be a little too upright, and altering the angle would mess with the side windows. What we want is a swoopy frame that evokes the styling of the 1930s coupes, otherwise known as a DuVall-style windshield. We just have to build it.
There are a couple of ways these things are done. We could spend months trying to hammer-form sheetmetal into the look we want, which an expert metal craftsman can handle, but we aren’t that skilled with a hammer and dolly. We could search for a car in the salvage yards to cut up and modify into something that resembled what we want, or we could start over from scratch and build a design that matches our ideas and doesn’t break the bank; with that in mind, we are going to cast our own windshield frame.
Technically, we aren’t casting in-house—that will be handled by a local foundry that specializes in small production parts.
We are designing and building the pattern for the mold. The pattern is the form that is used to make the mold itself. There are some critical features you must pay attention to when laying out a part that is going to be cast, namely drafts and undercuts. Draft is the angle of all sides when the part is laying in the casting position (how it will be sitting when poured). The vertical surfaces must have at least a 2-degree draft, and the base must be wider than the top. This helps in the release of the part. The other issue to be aware of are the undercuts. On some parts, like our frame, this can’t be avoided. To get the part to fit the car, there are going to be undercuts. This is alleviated through a two-part mold and a removable casting base called a “follower” that allows the top side to be formed, then the base is removed so the other half of the casting mold can be formed.
The bulk of the work on this project is done with mediumdensity fiberboard (MDF) and body filler. The design and build process is time-consuming, but it’s well worth the effort. Using the original frame as a guide, we built a rough copy from MDF, specifically the angle of the frame relative to the door glass and the tails that run into the doorjambs. Everything else will be altered.
We built the frame using superglue and brad nails. You want to build the frame base as sturdy as possible, as you will be removing and install-
ing the piece numerous times. The original glass was angled at 56 degrees; we don’t want to chop it—the original height is about right—but that angle is too steep, so we pulled the base of the glass forward 2.5 inches, which added 6 degrees to the rake of the glass (50 degrees total rake). For the glass to be at the same height off the cowl, the glass will need to be lengthened 1 inch, so this is sort of an “anti-chop.” We built an analog for the glass itself with ¼-inch Masonite and used that to create the actual glass surround, which was made with 5/8-inch MDF. Using superglue and wood blocks, this piece was positioned and glued into place.
Once the skeleton was built, it was time to start the styling. You can fill in the gaps and make a blocky frame, or go crazy and make everything swoopy. We opted for the latter. For this part of the process, we used a combination of body fillers, including Duraglass, which is fiberglassreinforced body filler, and standard lightweight body filler. The Duraglass is used as the base. This stuff can be applied thicker without worrying about cracking, and it is very strong.
Once the design was completed, the frame was prepped for casting and sent to the foundry. The casting process took about a month. The foundry built a casting frame called a flask and used a process called bonded sand-casting. Unlike green sand, which is fine sand mixed with oil to keep it
01] The original windshield is plain and boring. It has no style and does not fit the rest of the body. Time for it to go.02] We removed the frame and laid it out on some strips of medium-density fiberboard (MDF) and traced the shape onto the boards.03] The cowl piece has to match the original frame, so we measured the original and transferred that to the new base cowl piece. Even ½ degree off can wreck the fitment to the door glass.04] The frame has supports that run through the door hinges on the cowl, so we recreated those with strips of MDF and shaped it to match.05] The frame base was laid up with notched panels. This adds strength to the overall piece.06] The new base matches the original angle and fits the cowl well.
07] We created a pattern for the glass and marked a board with the shape. The line in the middle is where the wood gets recessed with a router and a rabbet bit.08] This becomes the windshield-frame glass form. We added ¾ inch around the glass pattern for a reveal.09] Keeping the top of the glass in the same position as the factory frame, we set the base forward about 2.5 inches, which gave us the 50-degree rake we were after.10] Once the base skeleton was formed, we started layering on the filler. This is all Duraglass for strength. We used masking tape on these voids, placed on the inside of the frame to keep the filler from falling out of the skeleton. We will bodywork the interior frame later. This process took several days to get the look just right.11] The interior of the frame is pretty simple; you can also see the glass channel.