Discussion
RicksAlfas said:
E90_M3Ross said:
Smaller than a whole rear subframe and other bits 
When I get the chance I'm going to paint it with the Bilt Hamber epoxy-mastic. I'll check later if it comes with the bushes installed.
That stuff needs the metal blasting to provide a key. I painted some underneath bits with it and didn't get a good result. When I get the chance I'm going to paint it with the Bilt Hamber epoxy-mastic. I'll check later if it comes with the bushes installed.
What state is the subframe in now?
The current subframe isn't actually too bad - I believe pics are earlier in the thread somewhere - perhaps April time. I figured they all "go" at some point, I wanted the whole suspension refreshing which involves the subframe bushes, so subframe needed removing anyway.....
E90_M3Ross said:
I messaged Bilt Hamber and they said it should stick fine if it's a clean surface.
They told me that too, but their spec sheet says it needs mechanically cleaning (or something similar) which means blasting and leaving a rough key. I wire brushed back to bare metal, then used the coarsest sandpaper I could to roughen it up and it was still not good. It doesn't paint as nicely as POR I don't think. Give it a whirl by all means, but as a big fan of BH products I was disappointed with this one.I would definitely use a scotch pad or similar to rough the existing coating up.
As above epoxy works at its best on a keyed bare metal surface. It's not really for overcoating, I'm assuming the new subframe is painted already? You might be better going for a 2 pack top coat such as jotamastic or similar.
As above epoxy works at its best on a keyed bare metal surface. It's not really for overcoating, I'm assuming the new subframe is painted already? You might be better going for a 2 pack top coat such as jotamastic or similar.
E90_M3Ross said:
Interesting.
At the end of the day the new subframe is going to last many years, and certainly many years more than the current one!
Absolutely but after going to all the trouble of changing it all you'd be gutted if the paint starts failing in a year or 2. Have a look at Jotun paints. Designed for marine use. At the end of the day the new subframe is going to last many years, and certainly many years more than the current one!
sdh2903 said:
E90_M3Ross said:
Largely a smooth, painted surface, but some imperfections.
Would I be better off with just Dynax UB?
I wouldnt try and epoxy mastic it. Either go for a more robust topcoat paint, or as you suggest go heavy on the dynax with a good few coats.Would I be better off with just Dynax UB?
I now plan to do just 2 coats of Dynax UB - I Have done 1 coat this evening on one side of the subframe (indoors with LOTS of tarpaulin under it!!), and I'll do the second coat tomorrow morning. I'm away all weekend so when I'm back I'll flip the subframe over and then do the same for the other side.
I'm weary about getting it near the bushes, and mounting holes etc so I may not be applying as much as I could. I'm spraying it, then brushing it in. Once I have done 2 coats and then get it fitted I will then get them to do another coat and be more liberal with it once everything is in place.
At the end of the day, it will last better than it otherwise would have! If I still have the car in another 10-15 years and it's looking crusty, and if the subframes are then NLA I would look to get it blasted and coated elsewhere. But the new subframe should last a very long time even if I didn't do the extra coating with the Dynax UB.
I'm weary about getting it near the bushes, and mounting holes etc so I may not be applying as much as I could. I'm spraying it, then brushing it in. Once I have done 2 coats and then get it fitted I will then get them to do another coat and be more liberal with it once everything is in place.
At the end of the day, it will last better than it otherwise would have! If I still have the car in another 10-15 years and it's looking crusty, and if the subframes are then NLA I would look to get it blasted and coated elsewhere. But the new subframe should last a very long time even if I didn't do the extra coating with the Dynax UB.
RicksAlfas said:
I'm impressed you're doing it indoors, but it does go on better when it's warm!
Yeah I figured as much, and it'd cure better too. I've just got a massive tarpaulin down. It's actually quite an awkward shape to do a very thorough job, I'm just doing the best I can. It's fully coated now, I'm away over the weekend so I'll do the second coat early next week and then remove all of the masking tape, then it's all done. E90_M3Ross said:
RicksAlfas said:
I'm impressed you're doing it indoors, but it does go on better when it's warm!
Yeah I figured as much, and it'd cure better too. I've just got a massive tarpaulin down. It's actually quite an awkward shape to do a very thorough job, I'm just doing the best I can. It's fully coated now, I'm away over the weekend so I'll do the second coat early next week and then remove all of the masking tape, then it's all done. d_a_n1979 said:
E90_M3Ross said:
RicksAlfas said:
I'm impressed you're doing it indoors, but it does go on better when it's warm!
Yeah I figured as much, and it'd cure better too. I've just got a massive tarpaulin down. It's actually quite an awkward shape to do a very thorough job, I'm just doing the best I can. It's fully coated now, I'm away over the weekend so I'll do the second coat early next week and then remove all of the masking tape, then it's all done. Basically I sprayed the top, outer and inner parts, left overnight, flipped over and sprayed the underside. I'll leave it over the weekend and repeat that process next week.
E90_M3Ross said:
d_a_n1979 said:
E90_M3Ross said:
RicksAlfas said:
I'm impressed you're doing it indoors, but it does go on better when it's warm!
Yeah I figured as much, and it'd cure better too. I've just got a massive tarpaulin down. It's actually quite an awkward shape to do a very thorough job, I'm just doing the best I can. It's fully coated now, I'm away over the weekend so I'll do the second coat early next week and then remove all of the masking tape, then it's all done. Basically I sprayed the top, outer and inner parts, left overnight, flipped over and sprayed the underside. I'll leave it over the weekend and repeat that process next week.
My pal when he was doing his E39 M5 rear subframe; he hung it off 2 of the rafters in his garage (just used strong bungee cables hooked onto 2 heavy duty decking screws etc); issue for him was stopping it all pooling etc, so he did little bits at a time...
Think it's still hanging there
He won't be able to work on it until Jan 2024 now, so it's just gathering dustMy only concern is that with the Dynax on they'll be something that won't fit properly now
I have no idea how long Dynax UB is meant to last (anyone know?) but, as I say, the rear subframe will at least be better than brand new, from a corrosion protection perspective. I would like to think the car will be alive in another 15-20 years, but obviously that's not likely for some other reason (eg engine, gearbox issues), although I can but try to ensure that it lives!
I have no idea how long Dynax UB is meant to last (anyone know?) but, as I say, the rear subframe will at least be better than brand new, from a corrosion protection perspective. I would like to think the car will be alive in another 15-20 years, but obviously that's not likely for some other reason (eg engine, gearbox issues), although I can but try to ensure that it lives!
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