Has anyone tried making their own bushes?

[cort16]

Has anyone tried making their own bushes? The reason I ask is the Alfa has a top engine mount (top left of the picture) and the bush at the engine end is totally mangled but the rest of it is in great condition. You can't just change the bush you need to change the whole mount, which is £90 and I'm a scotch tighwad.

 

 

I've had a look around tinterwebz and it seems possible to cast your own bushes using a pourable Polyrethane kit, which costs £20.

 

http://www.ebay.co.uk/itm/Poly-PT-Flex-70-Fast-Cure-Polyurethane-Rubber-500g-/220678509580?pt=UK_Crafts_Other_Crafts_EH&hash=item336176d40c

 

I was thinking I could clean the old bush out and cast it into the original bushing with a new mounting tube. Has anyone any experience of this?

Am I wasting my time or do you think it's worth a shot?

[Lankytim]

Iv'e heard that the best way to make your own bushes is buy a poly bar from ebay, stick it in the freezer overnight to make it hard and drill/lathe/cut as needed.

[cort16]

I was looking at these here http://www.directplasticsonline.co.uk/home.php?cat=6022 and it doesn't look too expensive but I'm not sure how you'd adhere the poly into the metal bushing. This bush needs to move in all directions and one of the things I'm not sure of is how do you stop it popping out?

[Albert Ross]

Would a Cortina void bush fit? Now that would be a shite fix.

[John F]

Would a Cortina void bush fit? Now that would be a shite fix.

 

+1

[cort16]

Would a Cortina void bush fit? Now that would be a shite fix.

 

They look similiar anyway. Have you got one you could they give me the dimensions off?

[Albert Ross]

Sorry. Nothing that new or small.

[Rocket88]

I have had a degree of success packing knackered bushes with Sikkaflex......................

[chaseracer]

Iv'e heard that the best way to make your own bushes is buy a poly bar from ebay, stick it in the freezer overnight to make it hard and drill/lathe/cut as needed.

Don't forget to trim your bush carefully. I believe the Brazilians have perfected this method.

[TimothyClaypole]

The Shore rating on the link you posted is 70, I use the same guy and the stuff I use for making moulds is Shore 30 or thereabouts so I would imagine that 70 is hard enough for an engine mount.

[cort16]

Sod it I'm going to give it a shot. If it doesn't work I'll create a a rubber mould of next door's cats face.

[CreepingJesus]

I once made bushes out of 80 shore nylon, which were going to mount a Ford 24v V6 in a 7 replica. They were turned out of bar on a lathe, which I think is practically the best way to do something like this.

The reason I'm saying that is: PU is fantastic stuff, and moulds beautifully when melted and poured, but you need a good mould to do it. The pro's will be using machined steel moulds, designed to accept any other sleeves or inserts as necessary, from the outset (PC a few months back showed exactly this on their article on Polybush), so the PU bonds to them straight off.

Supposing you recover the sleeves from your gubbed bush, and clean them up really thoroughly, and use them to pour the PU straight into; I'm wondering if the PU would back off a bit, as it cools and contracts (as things tend to do), leaving you with a poor bond. You could mount the sleeves in such a way that you'd get some runoff at each end, which could be trimmed down to a flange once it cooled (so you'd effectively have a PU bobbin with the sleeves trapped in the right places). I'm struggling to think of an easy way to do this, as it would pretty much have to be poured vertically, to ensure that the runoff was equally thick all round. At least, that's how I'd be tackling it...

One of these decades, I'll have a workshop, and it'll have a lathe which will do the low speeds necessary to cut plastics without them smoking the place out. And I'll dick about making stuff like this for fun - PU, nylon phosphor bronze...dribble dribble dribble.

Good luck sunshine, I'll be interested to see how this works out!

[jonny69]

I've turned mine out of both nylon and a softer material which I think is called delrin. Both worked fine.