Underseal/ Rustproofing Advice

[Smudgemanuk]

I am planning to rustproof my car however I have a few questions...

I don't mind it taking a while to apply but I am looking for quality and longevity

What brand underseal should I go with? (from personal experience)
Spray on or paint on?
Any other tips?

Much appreciated
Chris

 

[Brian Hill 1958]

My go to brand is Bilt hamber, used on several cars now. spraying is the only way to get proper coverage, in particular in the cavities. Obviously you need to remove as many panels/ arch liners as you can for best access, easy to do on a Z3

 

[DrWong]

Plus one for Bilt Hamber, all their stuff is top notch.

Their cavity wax comes in a spray can with a metre long lance, so you can jab it into holes etc. They also have an exterior wax which dries really thin and clear, so you can still see what’s going on underneath (i.e. vs thick underseal that hides any potential problems)

 

[Smudgemanuk]

Tempting... I have just ordered their touchless snow foam, but this sounds great too!

Just to confirm are you both talking about the Dynax-UB for underside and Dynax-S50 for cavities?

Spraying sounds more appealing to me anyway, that sounds like the best way forward

 

[DrWong]

Yep, Dynax UB and S50

 

[Brian Hill 1958]

Yep, UB for areas subject to abrasion and Uc if you want a clear coating on areas more out of the way