Undercoating Recommendations

[1690]

My '66 Mustang Coupe did not have protection applied under the new front fender after I had the car painted...it's raw steel. What product or process do you like? I'll probably apply it to all of the wheel wells do it looks nice, even and fresh.

3m rubberized? Something else? 

I won't drive it in the rain, intentionally, and I never take a hose to my car. I use waterless washes.

Thanks,
Nick

[J_Speegle]

Just for clarity - your not looking for a factory look just something to insulate and seal the wheel wells. Correct?

[1690]

Yes Jeff....not a show/concours car. It's my first car that I bought when I was 16, and I still have it after 32 years.

I would just like something that:
-protects well
-looks nice
-easy to apply

Thanks

ps: I also need some seam sealer too. I want to get into the wheel wells and really seal them off and make them look good.

[CSX 4133]

Rather than an undercoating you might want to consider a rust preventative paint which can be easily applied over new metal.

https://www.theruststore.com/Rust-Preventative-Paint-C112.aspx

[Bob Gaines]

Surprise to learn your fender underside is raw steel.  It should have been primed and painted before install.  More likely it was e-coated as purchased.  Makes a good primer to prepare for paint.

These cars were very poorly assembled.  I was appalled to discover how much under carriage and internal boxes sections were bare metal.  No wonder a daily driver would rot out in three years.  To best preserve mine during restoration, used Variprime self etching primer on inner fenders, radiator support, engine bay and entire underside.  Top coated with satin black Imron for best durability.    Then had Line-X applied to inner wheel wells and trunk drop section.  All internal, boxed sections typical of rocker panels, cowl vent, door posts and torque boxes were soaked with Fluid Film.  In winter car is stored on jack stands.  Spend hours detailing the underside insuring drain points are clear and no further corrosion is occurring.  As mentioned, keeping the car dry goes a long ways.  Is tough for folks from Texas - SoCal to imagine what salted roads and neglect could do.

Not just TX-SoCal because I have a certain NorCal friend that doesn't miss a opportunity to rub it in about the rust free zone he lives in .   

[J_Speegle]

These cars were very poorly assembled.  I was appalled to discover how much under carriage and internal boxes sections were bare metal.  No wonder a daily driver would rot out in three years.  ......................

Most/allot of these panels with cavities were originally not bare metal but but were glavanized but yes the basic desgin was a copy of the inexpensive Falcon car line

[1690]

So any other recs for a good and easy to apply coating?

3M?

[Jim Herrud]

Upon the recommendation of my enthusiast group, in 2003 I applied POR-15 to the chassis of my '65 Fastback. I am aware (ad nauseum) of the ensuing controversy surrounding rust preventative products in general and POR-15 in particular. There are many new choices for these products available today. However, my lot is cast, so at least that's one decision I don't have to make as I proceed with my build.

I was instructed to closely follow the POR-15 application recommendations and we tried to do so. Our chassis was completely stripped, soda-blasted and all compromised sheet metal was replaced. There was no rust present at this point. The chassis was cleaned, prepped with the POR-15 Metal-Ready and then POR-15 was applied with brushes. We complied with the temperature and humidity recommendations. The application was actually a fun experience as my wife and kids – including my 8-year-old daughter - joined me in the body shop on a Saturday & painted alongside me as the chassis hung on the rotisserie. The actual application is easy as the paint smooths out well and results in a hard, shiny surface. I've got a few drips and runs where I didn't catch them in time, but overall, I am happy with the result. You can find some underside pictures in one of my previous posts: http://www.saacforum.com/index.php?topic=822.msg6077#msg6077

Since the car has been in unheated storage for 13 years and in my garage for 2, the paint hasn't really been stressed yet. That said, I have seen no problems so far. Time will tell.

My concern now is that there are no front inner fenders to protect the underside of the fender metal. It is covered only with the POR-15. Friends have warned me about rocks or road debris getting kicked up, striking the underside of the fenders and creating damage visible in the paint on the outside top of the fenders. Similar to Nick's thinking (the OP), I am considering applying some type of rubberized/compliant undercoating, but in my case the purpose would be to cushion the impact damage of road debris. My car will be driven in anger. So, I have a few questions:
•   Do those of you who drive your cars at speed experience this damage? Or am I making a mountain out of a molehill?
•   If you do get damage, how are your front fenders coated?
•   Does anyone have experience they can share with applying a rubberized or other type of coating to the inner fenders?
     o  Has anyone tried bed-liner-type material like Line-X or Rhino-Lining?
•   Has anyone tried other solutions? I was thinking it wouldn't be too hard to make a rubber or plastic inner fender to line the bottom of the metal between the splash guards.

Thx!

[J_Speegle]

My concern now is that there are no front inner fenders to protect the underside of the fender metal. ............

So, I have a few questions:
•   Do those of you who drive your cars at speed experience this damage? Or am I making a mountain out of a molehill?

I would only ask you to reflect and ask yourself how many times have you witnessed damage showing through to the top side/pouter surface of the front fenders from all those rocks and such being tossed up onto those surfaces (race car or street car) after 50 years of not so kind usage?

Consider that most cars from the factory (by my observations and documentation) didn't receive any or just about any protective coating to those surfaces  and you can IMHO draw your own conclusions and plan from there

But if you want to be especially careful and the possibility  or even a chance of this happening will affect your enjoyment of the car go ahead. Sort of reminds me of all the people who worried so much about the gas tanks and the media hype (MHEO) about the subject and all the rear firewall that got sold out of that concern

[Don Johnston]

For some under body protection against corrosion, after doing all the correct primer and color painting, I did what cars now have on the top side to protect the paint.  Clearcoat.  Yup, I had a number of light costs sprayed underneath of of epoxy satin clear.  The Shelby is not going to a concourse car and I am more concerned about road junk and  corrosion from the bottom up in humid,  salt air climate.  The wheel wells are coated with rubberized undercoat for some protection from all the loose road rubble.