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NL320 outer door weatherstrip (pn 80341-09400?)


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Hi all,


I'm starting to get back into my NL320 project. I need weatherstrips for the windows. It has been a few years since I looked for them but I'm still not finding anything for sale (please, please correct me if I have missed something).


So I have started 3d printing molds with the intent to cast the rubber weather strips. Due to quality and reliability issues, i'm printing the molds in short segments of 60mm each which are then glued together to form the ~33" long mold for a single weather strip. So far so good, but I'm having a hard time selecting/finding the right rubber to use in the mold. I cast a small section of shore 60A urethane because I had some, but that is way to soft. I want to use silicone but I can't find anything stiffer than 60A.  I can find 70A, 80A and 85A  Urethane, but I'm not sure that is the best material and i'm not sure which hardness I should get.


Attached are some pictures of the test piece. I'm pretty sure I can for the real ones better if I clean up the molds better before casting. Dying black would also help. 


Does anybody have any experience and/or opinions on casting rubber? Or sources for materials? From what I have seen so far the materials are expensive enough that I don't want to buy a bunch of different types just to test them out.












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As I recall I tried the Roadster door rubber squeegee in its stock configuration but it didn't reach/touch the window, but it was a used piece.

I also tried the Volvo squeegee and it came up an 1/8" short of touching the window.

I just looked at my Roadster squeegee and it looks different than yours Steve, mine is not as thick at the end that touches the window, but if that center piece was cut off it might reach the window, I bought the set I have now from Tana years ago, the first set I bought in the 90s came from Ralleye.

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The gasket I use is 17mm across the top, but it is "L" shaped, the stock type is offset "T" shaped and that likely accounts for DylanFM's 18.5mm, the stock type gasket hides the channel the gasket is pressed into to hold it in position, I can see the groove with the gasket I use.

I just looked at both my L320 and my 1967 Roadster, the Roadster gasket appears to be large enough to reach the window, but that extra piece stevecar mentioned is an issue, the Roadster door has no real lip on the inside of the exterior door top while the L320 door has an 1/8th inch 90 degree lip, so if that middle/centered piece in the Roadster gasket was removed it would not surprise me if it would work, but I would need a good piece in hand to try it, keep in mind that all my 320s have good squeegees now, they just don't hide the channel if one is looking  to criticize the use of a part/gasket.

I paid $36.00 for 8 feet of the gasket I cut up to make a set of squeegees for my L320, I do not recall what I paid for my first set of Roadster gaskets back in the 90s, I got a deal for another set of them from Tana a few years ago, I would imagine they are expensive now.


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Sooner than later I'm going to take my 320 to have the front/back glass in and I'll see what my glass shop can come up with. They're the ones who figured out 61' Ford pickup back glass gaskets fit the 320 profile. They're also the ones who cut me a new windshield out of modern Jeep Commander glass.

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21 hours ago, DylanFM said:

I can post more info when I get home but the overall width is 18.5mm. From the window to the center leg is about 14.3mm.



I measured the Roadster rubber. I got the width as .723" (18.5mm is .728") and from the window edge to the furthest leg as .5" (14.3mm is .563")

Edited by stevecar
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I pulled out an old door to play with. I think the Roadster rubber would work, but in addition to cutting the extra piece off, the door channel might have to be opened a little to accommodate the thicker Roadster insert.

If Dylan is successful with his project, that would be a better solution. 


Edited by stevecar
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So what rubber should I order to try? Will urethane hold up outdoors long term? Is shore 80A too hard? Anybody have any thoughts? I have 12 of the 14 molds I need printed. I have sanded and glued 3 of them together and I think the finish will be acceptable. At least on the top, with the way I'm joining the molds the bottom side of the rubber may have more lines where the molds join together but I don't think that will be a problem. 


Long term I don't know what my plans are for providing these rubbers to other people. I'm not really interested in making money off of them but I also don't have a ton of time to make stuff for other people for cheap. One possibility is I could post the mold models online and anybody with a 3d printer or who can find a somebody with a 3d printer or who is willing to pay the print on demand websites prices can get their own molds. Somebody with a better printer than me could probably print them better than I do anyway.


I will have to see how much time it takes to make them when I'm done.

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I removed the poor window rubber from both sides from my L320. What a pain. It took well over an hour as the rubber was stuck and kept breaking up when removing. I cut the extra piece off the Roadster rubber and it fit right in, nice and tight. Unfortunately, it did not quite reach the glass. About 0.08" to short. But it looks much better than the old broken off rubber that was about 0.30" too short, and hard as a rock.

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You need to cut out the skinny piece in the middle.

Upon closer look at the glass, I am now thinking that the generic window channel that I used is contributing to the issue of the squeegee not touching the glass. The stuff I got was so tight that I could barely roll the window up or down. I solved that problem by trimming the inside to be flat, but that caused the glass to be not centered in the channel, further from the squeegee. So I think (not positive) the Roadster squeegee will work with the proper window channel. 

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If it doesn't actually scrape on the glass, it's kind of useless. That weatherstripping helps keep water out of the doors, and if you have a new interior, I would want to protect it. My 320 had to be kept indoors for fear of getting wet and destroying the brand new interior. Which is one of the reasons I sold it...

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This photo I posted a photo of elsewhere that shows the piece of Roadster squeegee touching the glass,  and the glass is actually touching the metal on the inside of the door as I don't have any window channel felt in that area.


The back side, the piece of paper is being held up by the glass, you can see there is no channel felt also, this makes me think that all 320 doors are not made the same or the squeegees are not the same.


If I had not already used other squeegee material(5/8" reach) I would likely use the roadster felt, you can see in the photo below that without any channel felt with my window against the inside metal door window frame the window is approximately 1/2" away from the the window from the squeegee mount channel, if I force the window to the middle of the channel(1/8") it is 3/8" away from the squeegee mount channel but that doesn't mean channel felt will force the window over quite that far, but on my door that is more than enough space for the 1/2" reach the modified Roadster squeegee has.


I am curious about what kind of space your door has Steve between the window frame and the top of the door sheet metal, mine is not quite a 1/16".




Edited by wayno
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It's not uncommon for doors to bend, which might account for the wiper not reaching the glass. One body shop trick I learned years ago was to simply twist the door back into shape with brute force.


Also, window tracks take a lot of abuse and can crack over time, allowing them to move around. Some are even adjustable, to a point.

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  • 4 weeks later...

So... I ended up ordering Shore 80A Urethane rubber and have been making these pieces in the  molds I printed with varying results. I think most of the window seals I have cast have been functional, but not necessarily cosmetically perfect. I'm getting some level of small air bubbles in the top surface,  and some visible lines on the top surface, and occasional large air bubbles in the non-visible part that goes in the door groove. That last defect caused or contributed to the first seal I installed splitting into 2 pieces right after I installed it. I think it was the combination of the a large air bubble in what should be the thickest part of the seal and that I had kind of stretched it while installing rather than pressing it into the groove.  The 2nd one I installed seems to be fine.


Pictures (please ignore the very dirty truck):










I have almost used up all the rubber I ordered and I think I have enough spares so I am unlikely to order more. What I'm wondering is if anybody else is interested in using this mold to create their own window seals? I have seen this type of thing done before where a specialty tool is mailed around to members of community for the price of shipping plus a deposit to try to make sure that it doesn't get kept by any one member. I.E, the first person on the list pays for shipping plus a ~$50 deposit, after they are done, the 2nd person on the list pays the first person shipping and the deposit, and so on. until the last person on the list returns it to me (or it is broken, lost, or otherwise no longer useful).  Any interest in that?


Or, I can sell this mold to somebody outright if there is interest in that. Personally, with the level of quality I am getting I don't feel like a could justify selling them at a cost that would make it worthwhile for me to sell them, but if somebody had more time then maybe it would be different for them. It takes about 45 minutes to an hour to make one with prepping and cleaning up the mold and then they need to set up for 24hrs.  


Like I mentioned before, I will put the CAD models for the seals and molds up on thingiverse.com in case anybody else wants to print their own molds.






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It looks good.

Would you explain a bit more the process of making them? Did you have to add color to get them black? How much would the release agent and the rubber cost to purchase and how many would they make? It sounds like there is a learning curve.



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The materials I used I got from Reynolds Advanced (AKA Smooth-on, but shipping was slightly lower from the Reynolds site).  Part numbers and cost:
Econ 80 - Trial Size    10016977    1    $27.78
Universal Mold Release - Aerosol Can    10001661    1    $14.36
UVO Black Tint - 2 oz.    10020842    1    $13.64
Subtotal    $55.78
Shipping $15.43

Grand Total    $71.21


The dye and the mold release will make a lot more windows seals than the Trail size of the Urethane rubber. This stuff is also available on Amazon.


The two part rubber is mixed 1:1 by volume and as a pot time of 13-15 minutes. I purchased some small plastic bowls and a set of measuring spoons for mixing and measuring from the dollar store. I have been mixing up more than I need which is wasteful, but I want to make sure I completely fill the molds. The "bottom" halves of molds (which are actually the top surface of the rubber seals) are all connected to each other with glue and a length of all thread running through them. The "top" halves of the molds are still in 14 individual pieces. The mold is a total is of 840mm long (~33") which is really about 210mm longer than it needs to be. Each section should require ~2.7ml of rubber to fill it up, but a lot leaks out the sides, etc so I have been using 5ml per section. 


This is roughly the process I follow:

1. Lay out the mold with all the top peices in the correct order

2. Spray all the mold sections with the mold release 

3. Measure out 3 tablespoons (45ml) part A into a bowl.

4. Put 12 drops of the black dye into the bowl

5. Measure out 3 tablespoons of Part B into the mixing bowl (for a total on 90ml).

6. Mix by hand and with a make shift whisk in my drill for a couple of minutes.

7. Cover the bowl with a paper towel and put it inside the canister of my shop vac, turn the shop vac on, plug the hose with a piece of plastic, and let run for 2.5-3 minutes. This is my make shift way of degassing the rubber.

8. Remove the rubber from the shop vac and start putting one teaspoon of rubber (5ml) into each section of the mold.

9. Put the top halves of the molds on, starting for the right to the left except for the last piece. The end cap of the mold on the right hand side has a lip so the top half of the mold needs to slip over and into place.

10. Put a ziptie around each section of the mold, except the the left most piece that isnt installed yet. Pull snug.

11. Put a single M3 bolt through each section of for mold. This it really to help with alignment, I don't even put nuts on them any more.

12. Put the left most top half of the mold in place. Because of reasons, the last piece seems like it is ~1/4" to long to fit and you have to flex the mold and kind of angle the last piece into place. If you do this before the zipties are put on the then the mold with start popping apart.

13. Ziptie the last piece and then pull all the zipties tight with pliers.

14. The goal is to complete all of this in 13 minutes. After the mold is filled, I think it is best to keep it as close to horizontal as possible in the large direction and at a ~45 degree angle from to back..


I added some pictures of the mold, etc, to the album that I posted earlier.




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8 hours ago, stevecar said:

Thanks Dylan!

Excellent write-up of the process. I had no idea it was that much work. They sure turned out great!



It really isn't that much work because everything is only takes about 20 minutes. The harder work in my opinion is cleaning up the mold afterwards. After 24hrs, I use a nail to press all the M3 bolts out (which can be difficult), then cut all all the zipties. The mold separates pretty easily, but you have to be careful to not tear the rubber seal if the excess rubber flashing is connecting the seal to the molds. The seal then can be pulled out of the mold, which again is pretty easy except where there are stray sections of rubber that have got done into the alignment holes of the mold. I then trim the excess rubber off the seal using scissors. I use a nail to press out any remaining rubber out of the alignment holes and clean up the rest of the mold and other supplies. The clean up and prep for the next molding probably takes 20-40 minutes and is kind of a hassle.


If I was to do it over again, I would put many fewer holes in the molds, try to do it in longer sections, do a better job sanding the molds (both on the inner mold surfaces and on the other surfaces to make clean up easier), and maybe glue alignment pins into the molds rather than have to press them out every time. This is actually what I am trying to do. Sort of just to see if I can, I am printing four 160mm mold sections with fewer holes in them. It is actually almost done with the first 2 of them (it could still fail), and then I will need to do 2 more. These are both the tallest and longest running 3d prints I have ever done (36 hours). The overall length of these molds will get rid of the extra 200mm in length that I didn't need and should make everything easier to manage. If they work, I will be able to test them out on my last 1 or 2 seals worth of rubber. If they fail to print or are too much of a pain to get sanded down right then I oh well.  

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