Popular Post Roman 14,662 Posted June 10, 2020 Popular Post Report Share Posted June 10, 2020 This feels like a bit of a crossover from a few other threads. However I feel it deserves it's own to make light of how easy it seems* to do some basic casting which can be really beneficial for old cars where parts are unavailable or expensive. So firstly, I'd just like to make note of that although its an absolute wanker to machine afterwards, it looks exceptionally easy to cast polyurethane. I thought this was a decent example of the process, or lack thereof - combined with some 3d printing for easy way to make the mould. On the more complicated level, watched this video for casting replacement indicator lights from resin was bloody cool. So good! The one thing that absolutely terrifies my about my older cars, is busting a tail light. They simply dont exist anymore. It's some level of comfort to imagine it might be possible to cast a replacement. That's all for now, as I've not actually cast anything myself! But hope to cast some useful parts over next few months hopefully. If anyone's cast some cool shit, feel free to post it up I would love to see it. 10 1 Quote Link to post Share on other sites
Scrubb 184 Posted June 10, 2020 Report Share Posted June 10, 2020 I'm keen to experiment with casting some car parts or 3d prints but I haven't yet due to cost of materials and not having a vacuum pump. Have you found anywhere in NZ that has reasonable prices for resin? Quote Link to post Share on other sites
Corbie 3,736 Posted June 10, 2020 Report Share Posted June 10, 2020 https://www.fibreglassshop.co.nz/ This is the local distributor for the stuff in the video. couldn't comment on reasonable pricing, but definately keen to have a play, some lens on my car that seem rarer than rocking horse shit. Quote Link to post Share on other sites
Roman 14,662 Posted June 10, 2020 Author Report Share Posted June 10, 2020 19 hours ago, Roman said: If anyone here has more smarts about this than my zero, I've ordered some of this https://www.barnesnz.co.nz/polyurethane/easycast-1306 Since I cant do any resin infusion stuff I thought I'd just dump this into my mould for gearbox crossmember and see what happens. Okay so this was a fuck up. It's 65 shore D hardness not shore A Shore D is for rigid poly and shore A is for flexible So shore D 65 is around Shore A 100, AKA stupidly rigid as you'd expect! This would actually just hold my engine up as a crossmember, rather than the rubber for it haha. However I'm happy with how well the layer lines have been minimized on the 3d printed mould with some filler primer. Even if some of it stuck to the part on the way out. It was crazy seeing how this stuff sets. It's a yellowy transparent liquid, like water. Then after a few minutes it almost instantly turns solid and white. Will try some 65A polyurethane rubber next. 4 Quote Link to post Share on other sites
Bling 21,886 Posted June 11, 2020 Report Share Posted June 11, 2020 I need to repair a tail light, remake fender mirror bases and indicator lenses would be a bonus at some point. Keen to see what people make in here. Cheapest taillight i've found was $250 + shipping from Japan, probably worse now due to exchange rate and shipping. Yeah I think i'll learn how to mold things... Will be sure to post up any progress with products used. Would be good to see other people doing so too. Saves buying crappy products if someone has used it with bad results etc. What sort of resin would you go with for fender mirror bases? I was looking to make a two piece mold, somehow, and make a few spares as I need two of each side. Might be able to sell a couple to recoup some of the manufacture costs. Quote Link to post Share on other sites
JustHarry 2,087 Posted June 11, 2020 Report Share Posted June 11, 2020 28 minutes ago, Bling said: What sort of resin would you go with for fender mirror escutcheon Fixed for future reference..... /ling 1 Quote Link to post Share on other sites
JustHarry 2,087 Posted June 11, 2020 Report Share Posted June 11, 2020 When you have some success casting them. I'd be pretty keen to do a couple for the crown fender mirrors. As the escutcheons are getting real had to find in good condition 1 Quote Link to post Share on other sites
Bling 21,886 Posted June 11, 2020 Report Share Posted June 11, 2020 Will let you know if I have success 1 Quote Link to post Share on other sites
Roman 14,662 Posted June 11, 2020 Author Report Share Posted June 11, 2020 Just now, Bling said: Will let you know if I have success Got a picture of what you need? Is it flat on the base? Quote Link to post Share on other sites
Bling 21,886 Posted June 11, 2020 Report Share Posted June 11, 2020 Imagine this sort of top design, with a thin angled tube on the underside. I broke my spoiler somehow, contents within. I don't actually have a picture of mine as it's been put away in a box for a rainy day. Getting pretty rainy so I should probably hunt it out. Flat base for the most part though. With raised sections under the mirror. Very similar if not the same as below. Bottom tubes locate the mirror on the guard and provide the space for the threaded rod to pass from under the guard to the mirror guts itself. 1 Quote Link to post Share on other sites
J-W-G 197 Posted June 14, 2020 Report Share Posted June 14, 2020 I had a look into this for my Cortina but the lens' look way complex to cast from a one peice mould... Looks like $500-700 per lens really is the going rate Quote Link to post Share on other sites
RUNAMUCK 30,217 Posted June 15, 2020 Report Share Posted June 15, 2020 On 14/06/2020 at 21:50, J-W-G said: I had a look into this for my Cortina but the lens' look way complex to cast from a one peice mould... Looks like $500-700 per lens really is the going rate Sure @- i5oogt - must have boxes of these?? Quote Link to post Share on other sites
- i5oogt - 2,961 Posted June 16, 2020 Report Share Posted June 16, 2020 14 hours ago, RUNAMUCK said: Sure @- i5oogt - must have boxes of these?? got heaps of mk2 ones. not so many/any mk3 ones sorry Quote Link to post Share on other sites
RUNAMUCK 30,217 Posted June 16, 2020 Report Share Posted June 16, 2020 Oh, mk3 (I'm not ashamed of my limited cortina knowlrdge) Quote Link to post Share on other sites
Roman 14,662 Posted June 21, 2020 Author Report Share Posted June 21, 2020 So I finally got around to mixing up some of the 65 Shore A polyurethane to see if it seems about right for engine mounts etc. I tipped some into the corner of the cut off bottom of a coke bottle. the results - aahhhh... It feels weird to give a review saying these mini boobs were about the right firmness but here we are. Definitely needs degassing, end up stirring a whole heap of bubbles into it that don't escape at all. This stuff is very gluggy compared to resin etc. It also took bloody ages to set. Like, more than a day. Very different to the solid stuff I used earlier which set in about 15 mins. I've been watching some stuff about bonding it to steel, sounds like you need to rough the surface with sandblasting, use a polyurethane friendly etch primer, then you'll get a really strong contact with the urethane poured against it. I guess only other thing is to make sure it's somewhat petrol/oil/temperature tolerant. I guess it would be seeing how many people use poly bushes for nearly everything. Will try find what sort of additive you can use to colour it. 4 3 Quote Link to post Share on other sites
ajg193 9,803 Posted June 21, 2020 Report Share Posted June 21, 2020 Might be able to use a different catalyst to kick it off quicker Also make sure there is no moisture in your molds as that reacts with the urethane during curing and makes bubbles - that's how they make polyurethane foam for seats and stuff. 1 Quote Link to post Share on other sites
kyteler 62,324 Posted June 21, 2020 Report Share Posted June 21, 2020 10 hours ago, Roman said: So I finally got around to mixing up some of the 65 Shore A polyurethane to see if it seems about right for engine mounts etc. I tipped some into the corner of the cut off bottom of a coke bottle. the results - aahhhh... It feels weird to give a review saying these mini boobs were about the right firmness but here we are. Definitely needs degassing, end up stirring a whole heap of bubbles into it that don't escape at all. This stuff is very gluggy compared to resin etc. It also took bloody ages to set. Like, more than a day. Very different to the solid stuff I used earlier which set in about 15 mins. I've been watching some stuff about bonding it to steel, sounds like you need to rough the surface with sandblasting, use a polyurethane friendly etch primer, then you'll get a really strong contact with the urethane poured against it. I guess only other thing is to make sure it's somewhat petrol/oil/temperature tolerant. I guess it would be seeing how many people use poly bushes for nearly everything. Will try find what sort of additive you can use to colour it. Not sure if relevant but I watch a guy on YouTube that makes softbaits, he puts his mixture in a vacuum after mixing to get the stirred in air bubbles out. 1 Quote Link to post Share on other sites
Roman 14,662 Posted June 21, 2020 Author Report Share Posted June 21, 2020 Yeah thats the way to go for sure. I've got a vacuum chamber here but my pump is chooched as I managed to fill it up with resin and damage the vane pump. Awaiting a replacement! 1 Quote Link to post Share on other sites
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