ZCar Forum banner

Status
Not open for further replies.
1 - 14 of 14 Posts

·
Registered
Joined
·
75 Posts
Discussion Starter #1
I understand that many people here have restored or partially restored z-cars. I was just wondering if any of you that have used bondo yourself or had a professional body repair guy use it for you, did anybody have problems with it. What's actually better, pulling dents to their perfect original shape or using bondo correctly to match the original contours of the body. and i'm not suggesting filling dents with bondo but using the smallest amount possible after pounding/pulling dents out or repairing rust areas. if done right would you even be able to tell the difference between reshaping the metal and instead using body putty(bondo).
 

·
Registered
Joined
·
93 Posts
Re: BONDO!!!

Pat,
What kind of question is that?
Of course you want to repair the problem as much as possible before using "bondo".
If you have rust or dents I dont know anybody who can restore the repair perfect.
If used right bondo will last the life of the car.
Terry
 

·
Registered
Joined
·
51 Posts
Re: BONDO!!!

Duraglass. it is kinda like bondo, but 5 times stronger. it is sold in a can like bondo. Bondo or duraglass is easy to use, just remember not to use to much hardner. about a pea drop to a 1 inch radius glob. The can pretty much tells how to use the stuff(bondo cans do). Pull the metal or fix the dent as much as possible. And if done right, you wont be able to notice the difference.

CHUCK
questions?
[email protected]
 

·
Registered
Joined
·
241 Posts
Re: BONDO!!!

whatever you do, don't cover any rust or holes with the stuff. rust has to be cut out, and patches welded in. then you use the bondo to smoothe the repair to original contour. if it is left open from the back, rust will form under the repair and will eventually rot your car away and a big chunk of bondo will fall out revealing a much larger hole to fix, with nice shiny year (if your lucky) old paint around it. Sad storry, don't do it. Best thing is to get the metal as good as possible, then just smoothe the imprefections with filler.
 

·
Registered
Joined
·
994 Posts
Re: BONDO!!!

GO AHEAD AND SLAP A TON OF BONDO ON...ITS GREAT....FILL THOSE RUST HOLES..NO NEED TO REPAIR THE HOLE WHEN U CAN JUST BLOB A BUNCH OF BONDO OVER IT AND WAIT TILL IT DRIES...THEN SAND IT OFF AND YOUR DONE.....GREAT STUFF......WHO NEEDS NEW FLOOR PANS WHEN THERE IS BONDO AND CARD BOARD!...JUST DUCT TAPE SOME CARD BOARD ON THE BOTTOM OF THE FLOOR PAN AND MIX UP A WHOLE GALLON OF THE BONDO AND POUR IT INTO THE FLOOR PAN...LET IT DRY PULL OFF THE CARD BOARD AND GET SOME BLACK UNDERCOATING AND WAL-AHH...YOU HAVE NEW FLOOR PANS...THIS ALSO WORKS ON QUARTER PANELS..BUT YOU PUT THE CARD BOARD ON THE INSIDE AND BONDO FROM THE OUTSIDE THIS TIME...LOL..I HOPE YOU GUYS DIDNT TAKE THIS SERIOUS...BUT I HAVE SEEN ALL OF THIS DONE...I HAVE LOOKED AT SOME REAL DEATH TRAPS WITH NIGHTMARE BONDO JOBS...SEE YA BONDO GUYS LATER!...JIM
 

·
Registered
Joined
·
241 Posts
I've seen worse!!!

What's even better is when someone takes an old t-shirt, dips it in fiberglass resin, then stuffs it into the lack of rocker pannel or behind a wheel, and uses the duct-tape and cardboard to hold it on 'till it hardens. I've seen soup cans used as patches, and they did'nt bother to peel the labels off first!!!! Old license plates seem to be fair game too.
 

·
Registered
Joined
·
1,047 Posts
Re: BONDO!!!

Chuck, bondo does make a filler called bondo glass. similler to "Kitty Hair" or "Gorilla Hair". also just to add to chucks post your 100% right about using just a bit of hardener. the reasion is the bondo, fiber glass, kitty hair, ETC.. what ever u use will be harder with less hardener. but it will take more time to cure. it will also be less likely to pop out of the hole or dent. if u fill a dent drill 2 or 3 holes in it and sand down good befor u add "BONDO" or any thing. it will have a srtonger grip
 

·
Registered
Joined
·
1,992 Posts
Re: BONDO!!!

Now, I keep hearing the word "bondo" in every post...and I'm thinking...I hope these guys aren't actually talking about using actual bondo instead of some of the other plastic fillers out there. Bondo was basically the best plastic filler that came out many years ago...but it hasn't chenged since then...if you want to make you're life easier and not pay much more, go to a body shop supply store and buy any of thier fillers. No matter which one you buy, it will be 10 times better to use than the bondo. It's less porous (less pinholes when dried), easier to work, clogs up sandpaper less...it's just all around better stuff, Take this from a pro in this area. I've been doing this for a living for years, don't use bondo unless you like doing things the hard way. If you don't believe me, go to a few body shops and ask what kind of fillers they use when doing repairs. I'd bet that not a single one will say "bondo" brand filler
 

·
Registered
Joined
·
2,676 Posts
It's unavoidable!

Bear in mind the number of qualified "panel beaters" out there are dwindling. There was a day when a good Panel beater could just about build you a new fender from a sheet. Bear in mind that to spend time working the metal ferfectly smooth requires time and time means money. Most good body guys will pull the metal as true as possible and use bondo to fill dips that could take hours to repair. If it is used properly the way it's intended it's great stuff. Problem is a lot of shops use it to actually build a new panel and shovel the stuff on, which has given it a bad name. Before the advent of fibreglass they used to use lead, and solder the dips and seams.
 

·
Registered
Joined
·
1,298 Posts
Re: It's unavoidable!

Hoo boy, lots of good points and a couple items that should be avoided.

My two cents worth:

I always repair the dent with hammer, dolly's, spoons whatever, to bring it out as much as possible to minimize the amount of "bondo" used. I personally prefer Marson, but there are many different brands out there of plastic filler. The composition, sandability and the porousness of the different brands is what will have some guys preferring one over another.

Using "bondo" as a generic name for plastic filler, like kleenex instead of puffs or whatever, is common. Just cause they say bondo doesn't mean "Bondo(tm)", it just refers to a plastic filler instead of other methods of smoothing a dent.

Generally, there is "light" bondo, this stuff will have a component within it that makes it lighter in weight than regular bondo. Most pro's won't use this, but backyard body men will use it cause they're making a thick patch of bondo. This stuff usually is very porous and will absorb water like a sponge.

There is fiberglass strand bondo, which will have names such as Gorilla Hair, Hi-Strength Bondo etc. This type of bondo has had fiberglass strands added to it in order to strengthen the over all filler. Generally this stuff is harder to sand and only used as a substrate for regular bondo. I have seen this used to patch holes, although I personally don't recommend it. However, there are times when you are rebuilding the back lower corner of an old time pickup cab, and you need the additional strength only cause it's a likely "hit" area, and therefore the additional strength of the fibreglass is required.

All bondo should be applied over as rust-free and hole free metal as possible. None of the bondo's that I've ever worked with should be exposed to the elements, the stuff WILL absorb water and WILL allow the metal below to rust, and eventually the bondo will just fall off. The practice of drilling holes to "promote adhesion" of the bondo is bogus. All you are doing is leaving a hole for water to penetrate. Use a 24 or 36 grit grind pad and gouge the metal, this is usually more than sufficient to have the bondo adhere.


I use 36 grit paper to shape the initial coats of bondo, and once I am "close" to shape, I switch to 80 grit to come close to "final" then I'll use 180 or so to smooth to final. Then I'll top coat with a good heavy coat of high fill primer and wet sand until the panel is proofed. Then the panel is subjected to primer and sanding just as if it were a perfect metal panel.

If you are filling or straightening a large area, it helps to fog coat between applications of bondo. This technique calls for applying a dust coat of primer or paint and then sanding with your long board or sanding pad, then using the areas where the primer / paint have NOT been removed as indicators where additional bondo is required. Then apply enough there to bring the "shallow" to the level of the surrounding area, and continue sanding to shape.

Generally bondo will have a "skin" that must be cut with an old piece of sand paper before using a clean piece of sand paper on it. The skin will tend to gum and clog a piece of sand paper so by using an old piece of sandpaper to scuff it off, you will actually save money on sandpaper.

A lot of times, after the bondo has been sanded to final shape, and you've primed, you may still have to use "red cap" ( another generic name for thickened primer) on scratches, shallows, or edges of the bondo. This stuff should be sanded down with 220 grit wet/dry sand paper, and then top coated with another coating of primer before applying your paint.

Just my two cents worth.
 

·
Registered
Joined
·
2,676 Posts
I don't think my E mail is working!

Using lead is a pain in the ass! I have tried it. Yo have to prep the metal
with tinning compound first. Then using a torch you solder the lead into
place and smooth it out with an iron. The lead sticks are a speacial type of
mixture made for this purpose and are expensive. Most of it will probably
end up on the floor when you grind it down to shape.
I am by no means an expert at doing it but I wanted to try it on my 68
Austin Mini, there is a definate skill aspect to it that I think would take
years to develope. I have also heard a lot of body guys complain that it was
the worst thing as far as corrosion. Apparently there is a lot of acids that
are in the tining compound and the solder that will eventually eat through
the paint, or so I've been told. I am sure there must be others that can
answer the question better for you.
Graham
 

·
Registered
Joined
·
1,298 Posts
Re: I don't think my E mail is working!

Graham is absolutely dead on. It does take a long time to be GOOD with lead, it is tricky, and you are always filling way way higher than you need simply so you have enough to shave / sand down.

The prep washes and fluxes necessary to make the steel ready to accept the lead if not properly neutralized will eventually leech through any primer / paint you use.

Also, don't forget the weight!

One of the biggest reason that "bondo" is so popular is that you don't have to worry about the prior coating melting when you apply a top coat cause you have a couple shallows.

If properly mixed, sanded, and allowed to cure / shrink before it's top coated, as well as a skilled body man, rarely if ever would you notice bondo use. The times I've noticed bondo underneath the paint job is when the person who applied it either didn't know how to sand it, or didn't primer and red cap or just plain rushed the job and didn't step out the sanding properly (i.e. 36 to 80 to 180 / 220 and then primer, red cap, wet sand and primer again)

One of the "secrets" is to NOT look at the surface as you feel it for irregularities. Let your hand tell you if it's smooth, run your hand palm open up and down the repair area, when you cannot tell where the repair begins and ends, and you don't feel any bumps, shallows or ripples is when that panel is ready for primer. If you can't feel it well, use a rag beneath your hand, you'll be amazed at how that rag will "magnify" the surface feel.

Too many novices LOOK at the repair and their eyes TELL their hand to feel a bump or shallow, and lo and behold, they do.

Two more quick "secrets", use the longest board / block that you can for the area, especially if it's a relatively flat piece or if it's contour is spread out. This makes it easier to sand to match the surrounding contour. The other secret is to sand in diagonal cuts to each other. Work your way down the length of the piece making diagonal parallel strokes, then on the return leg make strokes that slant in the opposite direction, run your board / block so that it's longest axis is parallel to the direction of your movement.

Don't fall into the trap of thinking that if the board / block spans the full width of the dent that the sand paper will magically stop sanding once you've reached level with the surrounding metal. I can tell you what an experienced body man calls these spots under your paint---Lilly Pads. Cause that's exactly what they look like.
 

·
Registered
Joined
·
2,156 Posts
they call me bondo bob

when in doubt
fill it in
 
1 - 14 of 14 Posts
Status
Not open for further replies.
Top