Bondo, is a two component epoxy putty, originally developed in 1955 by Robert Spink, a car repairman in Florida. Although it has changed in composition, it is still the foremost body putty used to repair irregularities in sheet metal auto body parts. I first discovered it soon after it came on the market while involved in repairing minor damage to first my, and then my family cars. It has a bad reputation with some people (a short cut and plastic), but certainly helps even out the surface after the sheet metal is pounded out to near its original shape. Although there are many other epoxy based putties now, Bondo still holds its own.
Since that time, I have found a multitude of uses for the material, from repairing damage to wooden porch floors in our 100 plus year old house, to stopping sewer leaks. I sometimes think that the reason the Roman empire collapsed was because they did not have Bondo.
But now I am worried a bit about the product. The company was bought in 2007 by 3M, a large and successful company, that is using the Bondo brand on a variety of consumer products. But I recently bought a new can of Bondo, and found that it was labeled as a “body repair kit”. The kit part apparently refers not only to the body putty, but also a tiny (2 inch square) plastic applicator, and two so-called self adhesive patches made of a metal mesh. I assume these are intended to bridge a hole in the sheet metal until enough Bond iss applied to seal the hole—but you don’t want to do that. You want to weld, or at least rivet in, a metal patch and go from there. And a two inch applicator? The “kit” part was downright insulting. Bondo is obviously fishing for the DIY (Do It Yourself) market, but it takes a bit of experience to use Bondo well, and probably more than a two inch applicator. I would suggest at least a reference on the can to one of the many excellent instruction videos on using Bondo available on Youtube . A fully set mishapen, lumpy mass of Bondo on his/her car would take the fun out of any DIYer's day (I incidentally am a veteran DIY person).
And I noticed the can was not full — hopefully not the grocery store game (keep the container size and the price, and cut the contents). Maybe Bondo cans were never full, but I do not remember that being the case. The attached photo shows the freshly opened can, the crème hardener and the “patch” folded around the tiny applier.
I also recently began using a wood filler now provided by Bondo, also a two component putty, that seems to set a bit softer, is more compatible with sanding and drilling, and can be stained to some extent. But it sets at least as fast (3 to 5 minutes after mixing). On a car, Bondo’s fast setting time is a benefit, because usually one smears it onto the sanded sheet metal over a fairly large and reasonable even area. Then one planes it (with a so-called cheese grater) and sands it with increasingly fine paper as it sets until one gets the desired result. But in repairing wood, especially in a house, it is not always possible to place the mixed putty in the proper place and smooth it as one might want to in such a short time, since house repairs often require a bit of acrobatics and forcing the filler into nooks, crannies, and crevices. But hopefully the manufacturers will realize that car body repair and the repair of wood products are often two different things, and at least come up with an option of a slightly slower-setting wood filler— how about ten minutes instead of five?
I am praying for the continued high quality of Bondo products. Hopefully, the long established reputation (brand) is not being used mainly to rapidly improve the cash flow of 3M. But marketing and potential quick profit have stolen the mind of many well meaning and venerable companies.