Trunk Roundel Gasket

dbower

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I would appreciate input from the forum as to the need for a sealant underneath the gasket. The setup BMW now sells does not provide a water tight seal against the trunk, and I am not sure that one is required. As Markos notes, however, it does appear that the original gasket did provide some level of a seal.

My interest in having a gasket is not weatherproofing but preventing metal-to-metal contact between the roundel and the trunklid.
 

eriknetherlands

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I would appreciate input from the forum as to the need for a sealant underneath the gasket. The setup BMW now sells does not provide a water tight seal against the trunk, and I am not sure that one is required. As Markos notes, however, it does appear that the original gasket did provide some level of a seal.

No need.
A seal could be added easily, by using a rubber washer on the inside of the decklid. Hence no need on the outside.

But as we are not allowed to drive in the rain, it is purely a hypothetical question.
 

steve in reno

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i would like to interject a possibility.

The base material of the gasket could be heated in the dye process to give the lip.
A cambered point will raise the other side. A press and cut.
Heated to give pliability to process.

Then when the badge is inserted it will be very slightly recessed. Best case scenario.

Just my $.02
 

Markos

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i would like to interject a possibility.

The base material of the gasket could be heated in the dye process to give the lip.
A cambered point will raise the other side. A press and cut.
Heated to give pliability to process.

Then when the badge is inserted it will be very slightly recessed. Best case scenario.

Just my $.02

Hang tight. Chris has been tied up so I'm taking the lead on this one. I have a 3D print arriving today via FedEx. We know that some changes are necessary but I will take the measurements and give feedback to my modeler (who has unfortunately doubled his rates since we started this effort). I'll add a pic to this response in just a bit.
 

mark99

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Doubled he rates? Was he giving you a bargain or did you piss him off?
You where planning on using the printed part as a pattern after some hand finishing or was the print the final part?
 

Markos

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I’m going to make it thinner and a bit less chunky on the ends. As mentioned earlier the plastic is UV stable ABS. I can also have it tumbled post print to reduce the stepping lines.

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Markos

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Doubled he rates? Was he giving you a bargain or did you piss him off?
You where planning on using the printed part as a pattern after some hand finishing or was the print the final part?

Printed part is the final part. He was under market price before but now he is above. I already found a local modeler to help me with other projects, but those are low priority for me. My current modeler will help me finish my outstanding stuff, including this gasket.
 

Markos

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does ABS respond to vapor polishing?

I don’t know what vapor polishing is. It sounds like a needlessly expensive post processing step. The printer that I use offers tumbling, and I use it on some parts.
 

mark99

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I would like to see the tumble, maybe it works fine
On some things. like prototype optics that we looked into, vapor polishing looked promising, but we didn't do it so I don't have any first hand knowledge
They put the part in an environment with a solvent vapor that melts the surface a little
Sort of like flame polishing plexiglass, but solvent instead of heat
But you are right, might be too pricey
 

Markos

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I will tumble the next print. The amount of visible plastic is so negligible that the subject isn’t worth much discussion. Buyers can sand the 1mm visible lip smooth if they are worried about judges holding a magnifying glass up to the gasket.
 

Markos

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I will keep everyone posted. I’ll send the adjustments to my modeler this weekend.
 

mark99

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I was thinking of making this myself, but I thought of a photo from a craft fair, there was a simple little decorative sign and next to it a note: "Sure you can make it, but when will you?"
 

dbower

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Bump. Just checking for any progress. BTW, SFDon shared with me that he found an NOS example still in the bag but apparently had shrunk up some after only 45 years.
 
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