MGB Trunk Carpet (Part 2)

Today, I complete the journey of carpeting the trunk of the MG (Oliver).

Catch-up

In my last post on this topic, I had papered the trunk to create templates. I drew lines with a thick marker to help identify the cut lines and then cut along those lines with a razor blade to create rough templates. I was able to collapse the rough templates for the wheel arches as well as the inner sides (referring to that area as the hip-walls) into a single reversable template for each. I cut the little dome into its own template as well as the little shelf into one. This left the rear firewall and main floor as the final templates.

Get Flat
The trunk, obviously, isn't flat. The wheel arches, for example are roundy, so once the paper molds came out, I needed to plan for making that 3 dimensional object flat. This meant careful cutting, removing v-shaped wedges from the outside pointing toward the axle so the paper (and eventually carpet) could curve when pulled back together. Since I had used small pieces of paper, I was able to leverage the seams as visual cues to what could naturally be formed. Ultimately, the wheel arches and the little dome were the only hard-to-flatten pieces. Since I had drawn the cuts along natural transition points, most of the templates fell flat without modifications. I decided to leave the main floor carpet until all of the rest of the carpet bits were completed. I know the main floor will require some different treatment, so I'll get to that at the end, or another post.

Template Test

one last "before" look

As a means of validating the templates, I traced each onto some of the U-Haul packing foam sheets I had used as a carpet backer for some of the carpet in the cabin. The sheets are super inexpensive, but if the templates applied well, I could use the foam both as a cleaner template for the carpet as well as a backing for it. Before I started tracing, though, I considered the points where the carpets would intersect and planned for overlapping tabs. This would prevent any gaps from appearing between the sections. For there, I simply added some blue tape along the side where an overlap would be and then taped sticky-to-sticky on the other side. This added about 1/2 an inch along those edges.

Once the overlaps were accounted for, I laid them out on the kitchen table and one by one traced with a marker. I needed to clean up a line here or there with a straight-edge, but generally I just traced and cut along the lines. As I completed each cut, I test fit the foam piece into place. Over the course of a weekend afternoon, I was able to form and test fit all of the foam pieces, including the rear firewall. The paper'd in rear firewall was unwilling to work well, though. So, I took the old panel from inside the cabin and traced that instead, figuring I could trim if I needed to. The foam fit perfectly, though. When I think about it, that makes some sense: it is the exact same pattern, just a tiny fraction of an inch more rearward. It should have worked.

Carpeting

wheel arch and hip wall done

Finally, the big fun could begin. I started with the 2 foam pieces for the wheel arches. I had planned the overlap tabs so I could work from the outside, in, and the wheel arches were the furthest out. The process was simple. First, trace the foam edge onto some carpet with a pastel (I decided that pastel made less dust-mess than chalk would have). Cut along the lines, glue the pieces together and then glue them into the car. That took less than 10 seconds to type and a sporadic weekend to do. Okay, it was really only a few hours, but dedicating that much time in one chunk can be difficult sometimes. So, it was wheel arches, then the side wall / rear side decks followed by the small shelf and little dome with the rear firewall last.In each case, there were overlap tabs from the prior section into the current section so no trunk paint showed through.

I used spray adhesive to get the foam and carpet to mate. I sprayed onto the foam, and then aligned one edge, lightly flopped the carpet onto the foam and then pressed firmly from the center to the edges. Once all of the foam-to-carpet bits were done, I cleaned the trunk with tacky paper cleaners that sell in a little plastic tube. Once clean, I considered that there were bits of trunk that were not going to be carpeted, but were not the right shade of orange, as painted by the prior owner. As I mentioned in another post, the Ace-brand rattle-can orange paint actually matches really closely, so I covered up the car with tarps and shot the inside of the rear quarter panels and the outer edge of he wheel arch. The paint dried quickly enough that I was able to continue the carpet steps later that afternoon.

carpet deum

To apply the foam/carpet to the trunk, I used brush-on contact adhesive. This is the same nasty smelling stuff I used to adhere the carpet to the speaker box. I simply brushed on a thin, but cohesive layer at one end, and applied the carpet as I went. This allowed me to make small adjustments as I went. This was especially important for the hip wall and fire wall carpet sections.

Trunk Floor
All of the story above applied for the carpet everywhere except on the floor of the trunk. I wanted to be able to remove that carpet section so I could clean or get to the fasteners for the fuel tank. So, while I was at Home Despot getting the brush-on contact adhesive, I picked up the end of the roll of rubber sheet. Being rubber, it will help keep the carpet dry if water gets into the trunk. It is only a few mils thick, but it worked perfectly as a carpet underlayment. I used the paper as a guide to start with, cutting the rubber sheet wider than the template at first. I test fit, trimmed with a straight edge and repeated that process until the rubber sheet fit perfectly. To cut the holes for the spare tire mount, the fuel tank filler and filler vent I traced a small paint can (for the first 2) and a quarter with a razor-knife. Once the rubber mat was set, I transferred the pattern onto the carpet. I found that the carpet did not want to move around once it was on top of the rubber so I didn't bother to adhere them together. For now, the carpet just sits on the rubber mat.

finished, box installed

So, that's it. Like so many of these projects, I spent much more time than I intended. It looks really good now, though. I re-installed the speaker box and it all looks like it was made to go together. I just have the trunk lid to resolve and the trunk is complete. I suppose I should find an old Honda donut spare so I have one that fits.

As always, thanks for following along. With the approaching nice weather, I think I will be shifting my attention back to the bus, and leaving the MGB in this state so we can drive it this Summer. Maybe I'll get to the interior next winter.