Hi not sure if this has been covered.
I am block sanding my 1971 w25 hood
it has been repainted atleast once maybe twice. It seems to be very uneven with lots of high spots which are down to a grey primer and the factory green still on some low areas. I am not sure how far down I should be going as there are now a couple white spots as well. Which I am assuming is the Smc fiberglass. Do I stop even though im not through the original topcoat? And what should go directly on the exposed smc?
My first post even tho I've had my W30 since 1989.

Thx
The Hammer

 

I assume the hood is off the car, if not it should be to make this job easier. The original paint was lacquer and can be stripped with lacquer thinner and an aggressive grade of scotchbrite. It is best to remove all the original paint but not absolutely mandatory. Spend money on some good chemical resistant rubber gloves for this job.

Don't knock yourself out trying to level sand the fiberglass. Fast build 2K Urethane primers are your friend here. They can hide a multitude of waves and the stuff block sands beautifully. Strip as much of the original finish as you can, Shoot a coat of DP90 epoxy primer over the whole hood. Locate the low spots and shoot a few coats of 2k primer over these areas and then a couple of coats of 2k over the whole hood. Block sand away and repeat application of more 2k primer until you get it where you want it.

Good Luck,
tc

 

X2. Don’t break the surface of the base material. Fill the low, take a compromise and call it a day. If you have a big dip, maybe a skim of filler would be appropriate. Think about what that material does between 50* on a cloudy day (or 0* in winter like I have done) vs 150* surface temp in the bright Sun on a hot day. It’s gonna move around a bit. Not saying you can’t get it dead nuts, but at what temperature? How many hours make it worthwhile? Even with good primers, you don’t want to build too much mil depth.

 

Wear appropriate respirators.

 

Excellent feedback thanks and double thanks.