BONDO , SPOTTING AND GLAZING PUTTY

Bondo is a two part epoxy auto body filler which is sandable. It could be used to fill seams, etc. on models, but it comes in large quantities, and it is designed for metal surfaces, so might damage model surfaces especially if it generates heat in curing. Spotting puttty is used to fill small dents and surface flaws on cars, and might be useful as a filler putty, indeed Squadron Green filler is a lacquer-based auto type putty. Haven't tried glazing putty, but most types don't dry, so their used for modeling might be pretty limited.

I believe glazing putty is a very fine smooth creamy type of filler used as a last coat before primer and paint. Bondo is a more course filler used as a base to build up a large area. Even with lots of sanding it does not produce as good of a finish as glazing putty. I can not comment on spot putty as I've never heard of it.

I do a lot of body work and paint in my job and this is how it was explained to me years ago. The names of the product may change, but the basic pricipal should be the same.

Oh by the way. I have seen these types of fillers used on a.b.s. plastic with no problems. I don't know how it would work with styrene.

Darren

The Bondo glazing putty is the red stuff in the tube. I use it for filling areas that are not too large. Little shrink, Drys fast and sands too.

modelmaker66

The Bondo glazing putty is the red stuff in the tube. I use it for filling areas that are not too large. Little shrink, Drys fast and sands too.

 

ditto for me. Wonderful stuff. Very specific to small, thin areas. It will crack in areas wider than 1/32” or if put on too thick (about same thickness, 1/32”). Great for filling sink mark. Also can be scribed if you’re into replacing raised panel lines or fixing existing panel lines. Dries hard, not really porous so it covers well when priming, i.e. it doesn’t show thru.

Bondo, polyester putty by another name, can be used for the really big fills.  As others have said, it is coarse.  It also does not feather well, and I have had separation from the plastic when there is slight shrinkage.  Thus I don’t use it as a surface material.

An unexpected behavior is that it gets soft when heated.  I made a fairly large “buck” covered with Bondo to vac-form over.  After a couple of pulls, I noticed the buck was starting to sag - and it was really hot to the touch.  When I let it cool down, it became rigid again.

Spot glazing putty is similar to hobby putty, but I find the filler to be coarser than the hobby stuff.  There may be several grades of spot glazing putty, so I probably got the rougher stuff.  I mixed it with Mr. Surfacer 500 and got a really nice cast armor texture.

The upside to using a fine grain automotive spot glazing putty is that the tubes are huge!  The one I have will probably outlive me.

Bondo is a brand name, not a single product.  They make spot/glazing putty as well as two part fillers, which are stronger than glazing putties.  The two part fillers can fill a larger volume, while the glazing putties are for shallow depressions and small cracks.  There are many brands of glazing putty.  I use glazing putty as my goto filler for seams and such.

 

Don Stauffer

Bondo is a brand name, not a single product.  They make spot/glazing putty as well as two part fillers, which are stronger than glazing putties.  The two part fillers can fill a larger volume, while the glazing putties are for shallow depressions and small cracks.  There are many brands of glazing putty.  I use glazing putty as my goto filler for seams and such.

 

 

I also use the red glazing. Comes in a tube, no mixing, little shrinkage. Kind of akin to Tamiya tube putty bu more product for less money. Don is correct as always.

IPMS40049:

 Bondo is a brand name for a two part auto body filler.They also have a Glazing Putty for tiny flaws. I use the Bondo ( it sticks great to rough sanded lexan) to finish out R.C. Boat Hulls. I use Rustoleum All purpose Grey primer for the first two coats of paint. 

This is one I use. Got it from the automotive store. It is very fine, sands beautifully. It is used for filling fine scratches in auto body work. Works on steel, painted surfaces, aluminum and plastic body parts. I've been working out of the same tube for about 5 years. Plus, I give some to the guys at the club every so often. I work out of a 1/2 oz Model Master paint bottle filled with it. That's how I give it to the guys, bring me a bottle - I'll fill it up for ya.

 

 

EJ

I use the red Glazing Putty to fill large seams. Easy to sand when dry. It works great on the nasty engine nacelle seams on Monogram big bombers.

Oh Yeah;

 Now there is what I really like. I had some problems getting it. All solved now. T.B.

Umm did anyone realize that this is a 16 year old thread

The last 10 or so posts are contemporary. But yes, Modelmaker66 ressurected a whole bunch of really old threads a little while ago. 

What kind of amazed me was how one finds 16 year old threads.

tempestjohnny

Umm did anyone realize that this is a 16 year old thread

 

That's OK, still very informative. People 16 years ago used to answer questions with good information. These days forums are so annoying and mostly a waste of time because everyone just want to make smart alec comments and the OP questions never get answered. This was an informative read.

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One of the really cool things about this old thread in particular is that MUCH better options for filling seams have come along since those days (2003).  It's kinda interesting to see a historical record of how our hobby is continuing to advance and evolve in so many areas.

I used some premix drywall patch once. Goes down extremly smooth and it did hold up to the spray paint with no issues. In fact alot of that stuff you can just use a wet finger tip instead of sandpaper to finish it off after it dries.