Originally Posted by Tatheelrod22
I've finished painting my spars with Interlux
Brightside following the instructed process for aluminum
and it has gone fantastic. Now I want to do the topsides and I'm confused about what I have to do to properly fair before painting. Today I ordered a 16" longboard, Surface Putty 257, Special Thinner 216,and the Brightside color which is the same color as the two part paint on there now (Black). From the spars project
I still have plenty of Interprotect 2000E, and Prekote left over. Here is where I'm confused. I was reading just now and it seems I can't sand, clean, and apply fairing compound over existing paint? Can I not sand the area good wherever I need to use the putty but still apply over the paint?I had hoped to get the wax and impurities off, sand with about 150 grit, then fair and sand with the longboard, then prime and paint. There are a few scratches that actually seem to have been painted over which is crazy. They need to be faired, plus when you look at the boat from certain angles you can actually see the woven pattern to the glass at the beam just below the toenail. I guess where someone sanded down too close to the mat and didn't epoxy over it. I've never seen that before. The boat is 43 years old but that can have anything to do with age as I've seen beautiful hulls older than that.
What are my options? Do I have to take all existing off to then get the surface fair?
Are you the guy that wanted advice re flatting agent a couple of weeks ago? If so, you never answered my reply to you, but I will try to help one more time.
257 is a spot putty; it is formulated to fix minor scratches and minor imperfections. It dries quickly and sands easily, but is not intended as a fairing compound. The labels on paint products give a lot of information.
What you are seeing on the hull
re the "woven pattern to the glass" is possibly a condition referred to as "print through"...common on many glass hulls painted black in areas with a lot of sun. Some resins soften at around 110 degrees F and the result can be what you describe.
To do a proper job does not require sanding
"all existing" off to get the surface fair. The determining factor is how much paint, putty, compound, etc. is on that surface now. No one can tell you how to treat your hull
over the internet
without seeing it, but fairing is the process of gradually filling low spots and eliminating high spots until all is perfectly smooth and level. If previous coatings have built up over the years more aggressive sanding
is required. If previous coatings have not built up and are tight and free of defect, then sanding and fairing will be much easier, and only spot putty will be required.
Bear in mind these are only general suggestions, and do not forget that the tech reps at the various paint manufacturers are extremely helpful.