By jpetrutis81
I'm finally starting my first build of a full-size pack. I have a GBFans shell and motherboard. Today I started to mark out where the mounting brackets should go before I start drilling the brackets (the whole measure twice, cut once mentality). When I looked around the motherboard for alignment I noticed a decent gap at the bottom of the shell. I don't think the shell necessarily warped but either way there is a gap. I am looking for wisdom from the group if it would be better to sand the shell to get a more flush fit or to use bondo or something similar to fill the gap? This area is the only area with a noticeable gap. If sanding would be the better option any ideas on how best to accomplish that (evenly) would be greatly appreciated. Thanks!

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By Prologic9
I basically had 3 issues with mating the GBfans shell to the motherboard.

First is undercutting. The shell appears to be cast with a line in it indicating where it's supposed to be trimmed. On my shell there was one corner where it was undercut and the line was still visible. So check if you have any of these issues and trim on the line. ( I could be wrong about the line as well, it could have just been something funky on my particular shell)

Second is general warping of the fiberglass. A little warping is acceptable as long as you can hold it flat by hand. To fix this you can clamp the shell down of a flat surface and heat it up with a heat gun and let it cool back down. Repeat as necessary. I'd also advise clamping it down like this to the motherboard when mounting it.

FYI don't melt your shell with the heatgun. If anyone melts their shell feel free to email GBFans on the weekends.

Thirdly is over-cutting. Your pic looks like over-cutting. I used bondo to fix this. Keep in mind anything within 1/4" is still perfectly accurate to the filming props. Mine wasn't really that large but it bothered me anyways.

There are other things you can do, maybe you have access to a giant belt sander? But this is what I did with this shell.

Here's a picture showing one of my clamps I used for heating/mounting/bondoing.

By jpetrutis81
Thanks for the insight! Fortunately I caught this early on so any mistakes and/or repairs will be taken care of well before the final painting and assembly. This is a work of love so it takes however long it takes. Using filler was what I was leaning toward as I was having a hard time figuring how to evenly sand the shell without the aid of any serious power tools. Is there any particular filler that would work best and anything prep-wise I should be aware of?
By jpetrutis81
Just a quick question... Did you use Bondo part 3 filler? I was at Wal-Mart earlier and they had parts 1,2, and 3. I'm thinking I only need the actual can of filler (part 3).

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