# Best paints to use on underside of car.



## M3simon (Jan 23, 2012)

Evening All.
I'm in the process of doing a underside refurbishment on my E46 M3.
http://www.detailingworld.co.uk/forum/showthread.php?t=401930

I'm planning to clean the full underside and wheel arches, wire wheel any surface rust spots, treat with POR15 and hand paint the full area.

My question is, what type of paint should I be using.
A guy on M3Cutters doing the same work, used a 2pack anti corrosion primer and then a top coat of 2pack anti abrasion teflon paint.
I must own up to knowing nothing about paint.
Any advice welcome.


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## M3simon (Jan 23, 2012)

I'm after something like the below


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## virgiltracey (Apr 19, 2017)

The guys that do a lot of refurbing in our owners club swear by a product called aquasteel.

Wire wheel off rust then apply aquasteel directly, no need for POR15.


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## percymon (Jun 27, 2007)

I'd have a look at Poobahs Honda thread..

http://www.detailingworld.co.uk/forum/showpost.php?p=5414228&postcount=216


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## Subc (May 30, 2008)

Check out buzzweld specialists in underbody coatings.

http://www.buzzweld.co.uk/


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## willywonker (Oct 27, 2016)

I've recently used Bilt Hamber Electox primer by brush, followed by their 2 part epoxy mastic again brushed on, both of which I found really good. I topped with their Dynax UB which I was slightly less excited about, but still like.

There was a 2 year long test in practical classics a few years back where I'm sure Bilt Hamber out performed POR15.

https://www.bilthamber.com If you email them for advice they're super helpful too.


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## moncris (Jan 2, 2018)

Another option is Raptor liner though it is a bit expensive.


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## VeiRoN (Oct 3, 2016)

Raptor is 2k isocyanate stuff afair,I woudn't touch it,BH is a good choice.



willywonker said:


> There was a 2 year long test in practical classics a few years back where I'm sure Bilt Hamber out performed POR15.
> 
> https://www.bilthamber.com If you email them for advice they're super helpful too.


Is there something their products don't outperform lul


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## M3simon (Jan 23, 2012)

Thanks for the advice guys.
I'm gone for wire wheeling all the surface rust.
Treating the areas with POR15, then 2 coats of Bilt Hamber epoxy mastic as a finish.


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## VeiRoN (Oct 3, 2016)

POR15 contains isocyanate,just an FYI.


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## Simonrev (Nov 26, 2012)

M3simon said:


> Thanks for the advice guys.
> I'm gone for wire wheeling all the surface rust.
> Treating the areas with POR15, then 2 coats of Bilt Hamber epoxy mastic as a finish.


TBH the POR15 isn't going to gain you anything ... Personally I'd replace that step with BH Hydrate80 and then the epoxy mastic


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## steelghost (Aug 20, 2015)

If you can get some galvanic protection on the bare steel (ie Electrox) that will give best rust resistance, with Epoxy Mastic over the top to protect from foreign objects.


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## VeiRoN (Oct 3, 2016)

steelghost said:


> If you can get some galvanic protection on the bare steel (ie Electrox) that will give best rust resistance, with Epoxy Mastic over the top to protect from foreign objects.


+1

To the OP,depends really if the part you want to paint is clear of rust or not,if it is then there's no doubt imo that using something like the Electrox (zinc rich primer contains 93%+ dry) following by the their Epoxy Mastic (available in black,grey or white) will give the best possible barrier against corrosion and by also having a very good impact/abrasion resistance,check out on the Bilt Hamber website for more details and the application method or post here if any doubt.


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## enc (Jan 25, 2006)

https://www.bilthamber.com/epoxy-mastic

can this be painted over. ie: use on sills then painted body colour ?


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## Simonrev (Nov 26, 2012)

enc said:


> https://www.bilthamber.com/epoxy-mastic
> 
> can this be painted over. ie: use on sills then painted body colour ?


Yep :thumb:


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