Radiator Mounting

posted Dec 3, 2012, 11:54 PM by Andrew Stock
Sorry for the delay in getting this post together! I meant to put it up this weekend, but my weekend ended up being a bit of a bust modding-wise. I spent all of Saturday putting up a fence in the rain for my dad, and Sunday shopping for xmas presents with the wife. Fortunately, I carved some time out this evening and still made some reasonable progress!

So, as I had indicated, I was in the process of repairing the bottom of the case from the large radiator holes cut out for the last cooling system this case housed. After testing out a few products, I landed on using some scrap aluminum to fit in the larger holes, then I used some Bondo bumper repair to put the whole thing together. This stuff is so incredibly versatile! Cheap, just flexible enough to avoid breaking under stress, tough enough to be drilled/tooled, sandable, etc etc. Has really been a pleasure to work with! 

I started out with a fairly thick layer to fill holes and gaps. I decided to fill in all the air holes in the bottom of the case, along with the other miscellaneous holes that were originally for holding up the drive cages, partitions, etc. 

I let that dry for a few minutes on top of a sheet of aluminum foil (which oddly it doesn't bond to, even though it bonds to my aluminum case just great... )

Then, a second coat of it to fill in the smaller gaps and imperfections in the first coat, giving a nice 'slurry seal' and leveling everything off:

I let that dry over night... then pulled off the foil and inspected the bottom side. 

Just a little bit of seepage through the holes, not too bad though. Should be easy to sand off. I then went through and filled in any holes that didn't quite get filled from the back side, along with sealing any cracks around the aluminum plates and such:

Then, I let that dry for another 24 hours. You can probably see why this took so long. 

Next day, I started sanding... oh... SO much sanding. This was an hour or so worth:

Turns out this stuff eats sandpaper alive. I went through all the sheets of 80 grit I had, then had to break and go to the store for more. 

After finishing the first round of sanding to satisfaction, I went for a final 'top coat' of Bondo to seal in any pits and such. 

24 more hours later... and a few hours of sanding with 120 grit...

And finally, the last pass of sanding with some 400 grit to remove the deeper grooves:

Man, what a production! But now the whole surface is baby's butt smooth, and should cover fairly nicely when I primer it. 

And now, on to the next task, and the whole reason I repaired the bottom the way I did... so that I can mount my radiator housing on it!

I started with a little planning and measuring. I decided I wanted to use the four 'spacer blocks' that keep the housing held together as the mounting points on the bottom of the case. Since the press-fit screw fittings worked out pretty well, why not use them again! 

I taped off the bottom of the case... not so much to protect it, as to give myself a good drawing surface so that I could measure out all the points where I wanted to drill:

I tilted the thing up on it's side to press the tape on securely, and one of the little wing tabs that keeps the case together fell off... doh...  Oh well, one more reason to use bondo!  It has good holding strength, but there's not a lot of surface area to work with here, so I am not so sure it will work. I may have to do an actual weld...

Anyway, I got the locations of the cross bars with respect to the bottom of the case all mapped out on the masking tape:

Then used the trusty drill press to punch the screw holes in the case...

There we go!

Maybe it's because it was getting late... or perhaps it was the epoxy fumes... but a little while after shooting the above photo... I realized that the plates and holes formed ridiculous faces. I couldn't stop looking at them every time I looked at the case... 


Now that I had the holes measured and drilled, I simply set the case on top of the radiator while upside down, and used a pencil to mark the hole placement on the acrylic blocks. A quick hit with the drill press, and a few taps of the hammer later:

And with some custom-cut MDPC screws/brainwashers:


And now, for the final challenge, and the part I was most dreading... the fill port / drain port:

If the measurements end up just a tiny bit off, or something doesn't fit together quite right... I'm in for some major headaches down the road. I started off by setting it just like in the picture above, screwing the whole system to the case so that I was positive it was sitting exactly where it would be going in the final build, then traced an outline with a pencil. Then, I set to work with the trusty Dremel and my up-spiral routing bit:

So far so good... now for the other part of the case that slips into the slot you can see through the tape above. I assembled the case, then traced the complete circle again over the tab that was covering up a portion of the hole I cut out. A bit more Dremeling, and a sizable amount of filing later... 

Bam! Perfect fit!

Phew! What a relief! Now I can sleep at night! 

Until next time...