Thread: Rear Window Garnish Molding Fix

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When I did the interior one of the things that bugged me was that my garnish molding on the back window was visible from outside, and over time it that back "wrap" had settled a bit on one side making it just "Butt Ugly", and something had to be done.

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When I did the "wrap" panel that fits from door to door, around the back at the window level, I simply used the garnish molding as the pattern for the hole in the panel, assuming that the molding fit the glass. So the first order of business was to make a sturdy pattern of the glass opening, and see how the molding really fits the opening. I guess I could just stick the pattern in place, advertising Free State Brewery in Lawrence, KS but I like to see out the back window, small as it is....

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When I compared the garnish molding to the pattern the top fits OK, with one spot near the driver's upper corner that has a slight gap, but the bottom is obviously arched up more than 1/2" in the middle.

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A yard stick shows graphically what the biggest problem is, but unfortunately the pattern of the glass opening is not exactly flat.

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I think the solution is to cut a piece of 2x4 to the exact shape of the bottom of the glass opening, round off the edge a little to mimic the inside of the garnish molding, and then use that as my "form" to re-shape the molding with some fiberglass mat & resin. I'll make some cuts in the vertical part, leaving the perimeter portion in one piece but flattening it to the form with some clamps. Once the bottom edge fits the space I can build up the spot in the upper corner with two or three layers of cloth, smooth it with a flap disc in an angle grinder, and get it ready to be re-covered in matching vinyl. When it all goes back in there will be some fasteners around the window to keep everything stable over time, and hopefully looking better.

Is that molding plastic? If so a little heat from a heat gun and you should be able to pull it back into shape.

Originally Posted by NTFDAY

Is that molding plastic? If so a little heat from a heat gun and you should be able to pull it back into shape.

Nope, it's molded fiberglass, and came with the body. I don't think that heat will work, but after I get the wood form whittled out I may give it a try, clamping it, heating and then releasing. Thanks for the thought.

The place I retired from made large collapsible containers from fiberglass reinforced plastic. On occasion they would warp out of the mold and if not cooled properly the pieces didn't fit together very well and we would use heat to bring them back into shape. Sometimes it would work and sometimes not and we had to be careful with the amount of heat applied and where it was being applied. Just a thought.

I marked & cut a piece of 2x4, then rounded the cut edge with a 1/2" quarter round bit, which fit the contour great.

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Looking at the back side, there's a nominal 5/8" gap at the center.

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At Ken's suggestion I clamped the molding to the form and applied heat to the outer ends, and then along the bottom of the molding. Thought it had worked when I took off the center clamp, but when the ends were released it sprang back to the original shape so I cut a series of reliefs in the front edge and did another test clamp.

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Next I'll grind away the gel coat across the front and 1/2 of the thickness in the cut areas. After a coat of wax on the wood form a couple of layers of fiberglass & resin should have it in good shape.

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OK, THAT didn't f^&*ing work!!

After getting the shop warmed up enough for the resin to "kick" I pulled it apart and the bottom sprung right back into the arch that it had originally!

After looking at it a bit I quickly realized that there simply wasn't enough "beef" in the molding section to overcome the natural arch that was cast into the part. Sooooo, the answer was to cut out the bottom section and use the nifty 2x4 "form" that I had made as a real form! I drilled a pair of locating holes near the corners, cut out the bottom section that had too much arch to fit, and mounted the molding to my form piece. With a bunch of cloth cut to 1.25" wide, the new bottom section took form quickly (took advantage of the fact that my wife was gone to tend to the twins and moved the operation into the kitchen ) DSC00623.JPGAn hour to let the resin react and the garnish molding now has the right shape!! Yea!!!!
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Now I need to take out the surround panel that has the rear window cutout, expand that cutout to match the new garnish molding, and get everything back in place. Should be better!!

And clear out the kitchen before the better half gets home.

Roger did you read any books on doing the glass work???
I have been looking for a good how to book but every time I go to
get a book some one tells me that book ain't good.
So is there any good glass books you could recommend for me to read???
Thanks Kurt

That should do the trick!

Originally Posted by vara4

Roger did you read any books on doing the glass work???Thanks Kurt

Kurt,
No, I didn't read any books. I talked to several people experienced in glass work, and picked up tips from them, as well as watching some of the weekly TV car shows like Muscle Car or the customizing shows that would occasionally get into some glass work. The guy who used to be on here with the interior shop in Nebraska, Recovery Room, gave me tips on using foam for forms for things like consoles or stand alone stuff. Other than that it was just jumping in and learning by doing.

Roger i feel your pain.. See how our body's came from the same place it no wonder we had some of the same problems... I ended up making a bunch of little cuts in mine to bend and form it to the shape of the rear window opening... at one point i had to cut it apart to move one corner around because i didn't like to see it when you looked through the rear window... a lot of glass work and in and outs but it came out nice.. I also did a lot of glass work on the side window molding to make them fit like i wanted... glassed an edge that went down in the door so when you looked down in the door from the outside you couldn't see down in the door..

You were more methodical than I. My approach was to cut a few relief's across the bottom, and when it didn't accept the new form I attacked with a cutoff wheel, discarded the bottom section and molded it new. Now the test will be when I pull out the surround panel, fit the garnish molding and see if it's invisible from the outside. If not then I foresee some more surgery!!

Great work Roger. I used to hate fiberglass work until I built my corvette. It was a lot easier to repair then a rusty turd, and it is kind of fun making the curves and such. Needless to say, I got good at making fiberglass repairs by the time I had my front clip together.

Originally Posted by rspears

You were more methodical than I. My approach was to cut a few relief's across the bottom, and when it didn't accept the new form I attacked with a cutoff wheel, discarded the bottom section and molded it new. Now the test will be when I pull out the surround panel, fit the garnish molding and see if it's invisible from the outside. If not then I foresee some more surgery!!

I see your point and at some point it might have easier to do the whole thing over.. but as you know working with glass isn't that bad if you have a lot of throw away gloves.... Hope your's fits nice when you pull it out of the mold.. even all the work i did i still had to pull it in place in a few spots with the screws but worked out ok..

Fiberglass window moldings just suck. I have two that I have hours of work in, and still need more.