Miata Hardtop Prep

Anything goes in the world of fiberglass and plastic



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PostPosted: Sun Mar 04, 2018 1:43 pm
I am prepping my hardtop at the moment and would like to know two things:
How far to sand?
and
Will 2k DTM primer be okay to use?

The hardtop was originally black and the previous owner had it sprayed yellow, so far I have been sanding all of the yellow off with 180 grit

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PostPosted: Sun Mar 04, 2018 5:20 pm
Well, my first thought was sand down to the black but it looks like you've cut through some places already there...... I'm assuming that is OEM primer poking through? If you could just keep that to a minimum you could seal with an epoxy primer, then go to a 2k build primer, guide coat, then block that all out nice and flat. Just remember, these things are made of SMC (sheet molded compound) fiberglass. That means they have a "release"agent literally cast throughout their material. If you would cut here or there into that material the epoxy coating would definitely be compatible at sealing that up.....
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PostPosted: Tue Mar 06, 2018 12:57 pm
Thank you Darrel, I did sand through to what I believe to be the factory primer in a few spots (forgot to take an updated photo). Of course this brings me to a few more questions:

1. Will a quart of epoxy primer be enough to get a few coats onto this hardtop?

2. How does someone go about sanding around the window as well as that back edge? Or just sanding in smaller areas?I've been doing these spots by hand and am curious to know if there is a better way

Thanks in advance

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PostPosted: Tue Mar 06, 2018 7:21 pm
Yeah, I think a quart with hardener should be close. If you are using an HVLP or LVLP gun you could do it. You're using it more like a "sealer" so you don't have to hammer it on....
As for the trim I've found this type of tool from our woodworking shop kind of helpful.....
https://www.harborfreight.com/oscillati ... 62866.html Yeah, yeah, I know it's another fine "quality" tool from Harbor Freight but download a 20% coupon and that's a pretty effective tool for detailing. Just don't go under 100 grit or so for detail stripping with it and pay attention to how level you keep it so you don't gouge with it. I use cheap masking tape as kind of a "guide" around the area of removal and that keeps me from gouging.
Metal, wood, fiberglass, we work it all... www.furniturephysicians.com We can restore the irreplaceable!

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