Rust treatment...

[NateWM]

Hey guys.

I need some advice about my rust problem. I had an issue with the car not starting after having rain. I eventually tracked this down to the rain running behind the strut tops, getting stuck between the firewall/inner arch and rotting through.

ANYWAY...I have stripped the dash out in preparation for welding. I need some advice on what products to use to protect the metal after the welding. Will i need a primer, or could I just whack some underseal straight over the bare metal? Obviously I need this to last, as I do not want this happening again in a few years.

Also, the water gathers in a very tight space where the firewall, inner arch and struts meet. Am i right in assuming i will need to put plenty of cavity wax down there?

Thanks guys!

p.s, Honda should be ashamed of themselves for not integrating a water drainage system for this very exposed area. I have checked 2 other cars like mine (one a type r, one a type v), and they both had rust in the same area. I shall be documenting this as i fix it, and will post it wherever i can to warn other Accord owners, as I have heard of others having problems with there Accord not starting after rain.

[V8covin]

If the bare metal is clean and rust free use etch primer,then normal primer followed by top coat...I'm assuming you're using aerosols

[NateWM]

Yes I will be using aerosols. I'm not bothered about the quality of the finish. The most important thing is that the fresh metal will be well protected, hence why I think a cavity wax could be needed.

[The Rustman]

Prior to welding, I presume you will be either DA sanding or using a flap wheel sander to remove any existing rust and paint back to bare metal. If you are not going to weld straight away then you will need to protect this prep with some weld thru primer. When the repair has been made clean the weld and seam seal with polyurethane seam sealant such as Sikaflex 521. This can then be coated with Epoxy-mastic high build rust protection this does not come in aerosol but it can be applied by brush. For further protection finish by applying a cavity wax. As it can get hot under the dash I would use a cavity wax with a heat rating such as Dinitrol 4010 Corroheat or Sikaguard 6215 both have a heat rating of 200c.

In my experience Honda are one of the better manufacturers when it come to rust prevention any further questions I'd be pleased to help