Ok, here's how I made my $215 radiator into a $320 radiator for about $12. As I mentioned in a previous post, the Nissens radiator does not have a metal reinforcement inside the necks where the upper and lower radiator hoses attach. I decided to blog this so that anyone needing to do something similar can learn from any mistakes I make. It is not necessary for you to own a 20 year-old Mercedes diesel to benefit from this-rather, it is to show you that a lot of the stuff mechanics and craftsmen are able to do is no real mystery. It is also to show how a little time, patience, and minor cash outlay can save a lot more money in the end.
After reading the recommendations on modifying the Nissens on ShopForum, I realized I could either purchase the kit the parts store sells, which is basically two pieces of copper tubing and some hi-temp waterproof adhesive, or I could buy the stuff myself, as a fair number of other members had done. Being in a bit of a hurry (Greta was now weeping THREE different fluids on my driveway), I shoved off for my local Orange Box Warehouse Home Improvement Center. Think what rhymes with "cheapo". There I found what I needed. Two pieces of copper tubing with the proper outside diameter of just over an inch. The pieces at my store were reducers, so they narrowed down to a smaller diameter to fit a smaller piece of pipe. Their real use is immaterial, as we are using them in a state altered from the original anyway. Should you ever need to do this, get your measurements off the inside of your neck-the OUTSIDE diameter of your copper piece should be the same or very close. A snug fit is ideal, but you can build your adhesive up. Check your junk pile before you go buy something! Repurposing rules.
(I thought about the copper oxidizing in the radiator, but truthfully I would not know where to begin looking for either aluminum or brass tubing to do the job, plus there had been no problems reported with anyone who had gone the ShopForum route and used copper. I figured if worst came to worst I would remove my hoses periodically and take a toothbrush to the copper to knock back the cupric oxide that formed. I doubt it will be a problem.)
Next came the proper adhesive. Again, I had done some prior research, looking through spec and MSDS data sheets to see what would work best. In the end, I could have just taken the advice of the forum members. JB-Weld is a fantastic substance that comes in two tubes, and is activated upon mixing the steel resin filler and the catalyst together in equal parts. The result is a steel-hard substance that can be filed, tapped, drilled and machined. If you could actually weld it, it would be perfect. It withstands a temperature up to 600 degrees (far higher than the 225 or so in my radiator), is waterproof, and also chemical resistant-I'm hoping the formulation of antifreeze will be one of those chemicals, but again, research has told me this won't be a problem. One package is more than enough to do the job, and will actually leave you with plenty for other repairs. Make sure you get the original JB-Weld (black and red tubes and packaging) and not the newer JB-Qwik(Blue and Orange tubes)-The Qwik is not suited for the higher temperatures. I have used JB Qwik on other applications, however, and found that under less-than-extreme conditions it is an ideal adhesive/filler.
(The coolest part about JB-Weld is the old-school packaging-look at that old clip-art!! and an oval blank for writing in the price at the top left! In an era of UPC scan codes, this is way cool!)
Once home, I took my reducers and placed the narrow ends over the end of an old broomstick before placing them in my shop vise. This way, the copper would only deform as much as the wood beneath, and the length of my stick would help grip in the vise, letting me saw without the piece falling out of the vise. It also did not matter if the smaller piece deformed, as it was only going to go on my copper pile for recycling anyway (copper prices are way up, BTW).
(Make sense now? The broomstick keeps the tubing from oval-ing and then grips the rearmost part of the vise jaws.)
After some careful cutting, I had the pieces I needed. I cleaned them up on my bench grinder, and finished them off on my drill press with a tapered abrasive bit-the main idea was to get rid of any burrs that may do damage to the hoses, and to remove any hanging copper that could find it's way into the cooling system. You don't have to go crazy, but do a good job smoothing them out. In the absence of a grinder or press, a Dremel tool or hand file will to the job just fine.(piece on the right is not perfect, but probably as acceptable as anything that has been on the last three Space Shuttles that blew up.)
Now comes the messy part. I took a small paper plate and laid out my beads of Resin and Hardener from the JB-Weld package. I keep a small stack of cocktail plates for just such an occasion, but a word of caution-styrofoam plates will usually soften or melt from the slight chemical calalyzation of the JB-Weld. There is a slight heating action that takes place as the product cures, and it has left me with a mess on exactly ONE occasion-when I used a styrofoam plate as my mixing palette.
(equal amounts are required to make the JB-Weld work properly)
I also prepared a few mixing sticks ahead of time-two craft popsicle sticks are sanded down on the grinder for a more fine tip:
A bit of brisk mixing and the JB-Weld is ready. It should look like this when done-well blended and no white or black streaks in the mix:
The next part was too tough to photograph and do at the same time-I smeared the JB-Weld on the outside of the tubing, putting most of it on the side going into the neck first, to allow it to spread upwards to cover the entire outside of each piece. Your pieces will slide in fairly loosely, really only hindered by the adhesive. Once they are in place, wipe off any excesses and stand the radiator on its side-gravity will pull the tubing further inwards if you leave the necks facing up. After ten minutes or so check the fittings to see if they have migrated inward-if so, pull them back out and clamp them in place. JB-Weld will fully cure in about 15 hours or so. If you have left any excess anywhere that has dried, no fear-remember the stuff can be sanded off with paper or a Dremel tool if necessary. Try to get any excess inside that could be prone to flaking off in the future, and thereby clogging your system.
(The whole works will look like this once you get it in there-carefully wipe off all the outside excess....)
(aaaaand...you're done. Anything on the inside is easier cleaned after drying of the adhesive [with your dremel, file or sandpaper]-make sure you face the necks downward/outward when removing any debris, to keep the crud out of the radiator, and ultimately, your cooling system.)
Next step will be installation of the transmission cooling lines from the old radiator. Stay tuned.