Raw black rubber

[Russ BParticipant @russb]

I'm a bit late to the party.

I've had great success using 2 pack urethane – it's as tough as old boots and can be coloured. Available in a range of hardness, I get mine from Bentley Advanced Materials, it isn't cheap but it is good quality – their colour pigments are UV resistant which is important for your application!

Silicone has a much lower resistance to hydrocarbons/oils/fuel – I wouldn't advise it on a car, but on the back lights, maybe ok?

I 3D print the moulds and give them a final finish (what ever is needed, a bit of sanding, a touch of filler, a coat of XTC3D and a final spray of release agent (as urethane is a very strong adhesive IIRC)

I cast a seal face on a 3D printed conical sealing head, using a 3D printed mold, for a 1 ton per hour pulverised coal injection machine running at upto 7 bar, the seal head is on the main bulk material inlet, I built the machine a few years ago, and it's still running today.

[Russ BParticipant @russb]

Sorry Hacksaw I didn't see your post regarding having already tried PU!

This unvulcanized rubber sounds like the business. I might investigate further although I believe it's not capable of retaining pressure which would be of some importance to me. How much was this stuff and does it have a shelf life?

[David George 1Participant @davidgeorge1]

Hi most parts like these are moulded in an injection moulding tool and I have made tools for pump seals, pipe flange gaskets, and conduit seals. Short run dies were cut in dural aluminium and were very basic. The material is very easily available to moulders and comes in a small pellet form.

David

[Dave MartinParticipant @davemartin29320]

Hacksaw,

Before you go to any work or expense, especially if this is something you're planning to sell, would suggest you ascertain the hardness of the parts you're trying to replicate (usually measured in Shore, but important to know which scale it is measured – commonly type A or D, but also type O and others – a tyre might be 70 on Shore A, but 70 on Shore D is a hard material like a plastic safety helmet). Once you know your target Shore then you can source materials, and check your end product matches the original.

[CirclipParticipant @circlip]

Backing "cushions" are usually molded in compression moulds, at least those made by PMG Thorpe and Rubberlite were. Dump a lump of the black stuff into the cavity put the lid on a squish and bake. Excess was/is catered for with a spew groove and when cured, the excess is torn off.

(Second company I worked at after my avatar name)

 

Regards Ian.

 

 Would be surprised if there isn't an original manufacturers logo on the inside of the molding. Fords wouldn't have made it.

 

 

Edited By Circlip on 01/09/2017 14:53:32

[HacksawParticipant @hacksaw]

Posted by Circlip on 01/09/2017 14:50:02:

Backing "cushions" are usually molded in compression moulds, at least those made by PMG Thorpe and Rubberlite were. Dump a lump of the black stuff into the cavity put the lid on a squish and bake. Excess was/is catered for with a spew groove and when cured, the excess is torn off.

(Second company I worked at after my avatar name)

Regards Ian.

Would be surprised if there isn't an original manufacturers logo on the inside of the molding. Fords wouldn't have made it.

Edited By Circlip on 01/09/2017 14:53:32

Well ,that is what i'm doing…

[HacksawParticipant @hacksaw]

Posted by Dave Martin on 01/09/2017 14:00:21:

Hacksaw,

Before you go to any work or expense, especially if this is something you're planning to sell, would suggest you ascertain the hardness of the parts you're trying to replicate (usually measured in Shore, but important to know which scale it is measured – commonly type A or D, but also type O and others – a tyre might be 70 on Shore A, but 70 on Shore D is a hard material like a plastic safety helmet). Once you know your target Shore then you can source materials, and check your end product matches the original.

Remould tyre goo is just right… just waiting for it to arrive.I'll post up my results when i'm done..

[HacksawParticipant @hacksaw]

Some other Mk1 parts i remade ..Thermostat housings for 1600 xr2 and 1300 . Like this, but a smaller outlet elbow . Cast dozens and sold them all on ebay and the club . I made this one for an Escort 1600 Xflow with a temperature take off modified for an electric fan . Cast and machined in da forge !!  No CNC here…

 

 

 

 

 

 

XR2 round headlight adjusters and clips …in HDPE . For these I bought a benchtop injection machine from a school, made the moulds and made hundreds of the pesky things !! Screws were modified stainless items . Made more money by selling the machine back to another school ..

 

 

 

 

Edited By Hacksaw on 01/09/2017 17:10:41

[HacksawParticipant @hacksaw]

Did a bit of corner filling of the mould ,with weld .. and power filed it back to a better radius . Made 2 plates , to fit the front and it bolts together ok… then i gravity filled it with 2 part urethane / silicone stuff i had , clamped it together and left it to cure..what a mess !!

 

 

 

 

 

 

1/2 hour later I HAD to see what it looked like…Too  soon , the rubber had stuck to the bolts and as i undid them , it tore the casting .. and there are a few voids , but hey ho , it's looking promising . Can't wait till i get the vulcanizing rubber and cast it under pressure

Edited By Hacksaw on 02/09/2017 18:48:55

Edited By Hacksaw on 02/09/2017 18:57:15

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