Polyurethane filling ?

[PATDIESEL]

I see that some of you have used some polyurethane filler for your motor mounts from McMaster. I'd like some more information on what you bought since I can't seem to find a real good description on their website as to what the products are and what they could be used for. I plan on trying to make some more bushings for our cars using this stuff and a mold. I know that Luc used Nylatron preformed parts and then cut them to fit, but I think this would be easier and hopefully I can find a liquid filler that is graphite impregnated so that their are less squeeks. So what I need is some more information or alternative sites that have a good explination as to what the polyurethane product is and it's common uses. I appreciate any help.

[lakersfan1]

The way the McMaster website is set up, you have to initiate the search using a keyword. Type 'flexible urethane' in the search field to begin. Click on "Flexible Urethane Casting Compound" when the search is done. That should bring up a catalog page. Scroll to "Casting Compounds" The first three are the ones most people use. 60A is softest, 80A medium, 94A hardest. You can try screwing with the other casting compounds for different applications, but I don't know anyone who has used these.

[bmwm3guy]

Theres a good post on here about this. Im about to do my mounts with the Putty Casting Compound 60A weight. Ill take some pics in the process and post a how-to later on.

[Macen]

I got my order today. Ordered the 60A. Will fill my old mounts.

[babyblueMX3]

yeah same here got the 60a mcmaster urethane..will do in a week or 2

[mdavis]

I haven't filled my mounts (actually just installed MS mounts today) but pretty much all i've heard from people who have actually done it is that the car rattles way too much and many peeps remove them within a week or so... Perhaps cut foam or something to fill part of the mount with so the urethane doesn't fill the mount all the way, and drill holes in it afterwards (I forgot who did this, but i remember reading about it)

[Macen]

Hm... and why do people talk so much about filling them if it's not good? *confused*

[IanL]

Originally posted by Macen:
Hm... and why do people talk so much about filling them if it's not good? *confused*

Its a matter of degree. Some people have "tired" mounts that are not stiff enough to resist the extra torque of the KL, some just think the standard mounts are not stiff enough, some have torn mounts and use the filling as a sort of repair.

If you are fitting new mounts, and want to cater for the extra torque from your KL, you could put a little extra filling in, but not a lot - it's a matter of judgement.

[Macen]

Oh, ok. I will use my old mounts. Hope 60A will not be too hard. Want a quite smooth ride too.

[bmwm3guy]

60A is much softer than 90A. I have read on these forums that some people drilled holes in the urethane to give it a bit of give when they found it too stiff. Drill the holes at 90 degree intervals.

[mdavis]

hmm.. with the KL and a clutchmasters stage 2 I clean broke the front tranny mount rubber all the way through so you can slide the middle chunk out... fyi..

[MazdaManiacMx3]

I used 3M Window weld polyurethane for the mounts , worked well not too stiff and doesnt squeak.
You can purchase it at A&A auto parts
Kris

[mx3-ze]

I ordered the shore 85a flexible putty. It has a very high tensile strength and is very easy to work with. I mixed the whole jar so I knew the ratio of the two parts was correct. Stir the two parts together and it will turn into a thick gel.
I put the mount on newspaper and spread the putty on one side until it filled all the voids and came out the other side. Then used a wide putty knife and spread both sides smooth. I dont think the ride is harsh and I dont get any wheel hop at all.McMaster Carr #8644k13