Body Filler and Lead: One Man's Opinions

[ossodiseppia]

Quote:

Originally Posted by Stathy Since we're on the topic of rust/pin holes, what are your opinions on areas of metal that have been stripped to bare metal but look like Swiss cheeze? Does braze welding (bronze) work well in this situation or is the cut and replace method the only way to go?

[esc2064]

Thank you Mike! You've given me a new direction on my current resto.

Elcid

[PAINT4CARS]

Great info on body filler here. I'm sure you cleared us some confusion and issues for many people. Great job!

[John B.]

Quote:

Originally Posted by GoldCloverLeaf Ok last post i swear :P Taken from another one of Mikes informative posts: "As people have mentioned elsewhere, many will prime the entire car with epoxy and do the bodywork on top of the epoxy. The advantage to this is the epoxy protects the metal while the bodywork is being completed. The disadvantage is the body filler creates a stronger bond to bare metal than to epoxy. The manufacturers officially do not recommend this, but will admit that it has its advantages. I do not do this."

[ga_mtn_spider]

As well we should not forget that heat causes condensation when applied over bare metal will cause rust which we see a lot in old lead jobs, but this is (according to I CAR) the reason for the epoxy primers under modern fillers, not so much for adhesion but for controlling rust. Modern fillers while under going their chemical change heat up and yes can form condensation on bare metal. I also was uneasy applying filler over cured epoxy even though the paint companies tell you it is o.k. I still prep my panel or grind like I normally would, apply epoxy,: once it has cured then hardblock the area with 80 grit before applying the filler

[Ablewood]

Quote:

Originally Posted by Timo Mike, Thanks for explanation of body fillers and their proper use. A resto shop owner once told me the exact same thing about the mis-use of bondo/body fillers and how these products are getting a bad rap because of it. I'm currently doing a brand X rolling resto job on an old BMW. I was wondering what you thought about using the aformentioned body fillers(any and all the ones you mentioned)and if they were suitable for filling up small holes in the panels where some "aftermarket crazed idiot" (pardon my judemental expression) mis-drilled holes for mounting non OEM badges and name plates ect...in places where they were not meant to be. These holes for mounting the badges seem to be farily standard in size for most cars and in this case they are about 1/8 in diameter maximum. Most, if not all, of these holes will be covered by the badges when they are remounted in thier correct location. Do you think it better to just weld them up as opposed to using body filler? Thanks in advance.

[EdP]

I just joined this forum, but I thought I'd chime in. I too hold to prepping the bare metal before ANY filler. This being both an etchant wipe, followed by etch primer. I know, a little redundant, but once a body is media blasted or sanded bare, rust can start forming microscopically in seconds under the right conditions. Doing the etch first helps insure long time no rusty!!

[Talawahlion]

Evening all,

An excellent "Body Repair 101" post. I would like to get some repair work done here in NY City on my 87 Milano - It has plenty of rust. As I'm a student my resources are extemely limited. Do you know of anyone in New York who has worked on Alfa before and therefore understands all the nuiances associated with repairing these timeless classics? I would appreciate any help on this one.

Thank you.

Jr. Lee

[alllfa]

fellow bb members. Please excuse my ignorance but i am half way through the restoration of my car, i have removed the rust in sections and welded new metal on top of my repairs. I will now require a light coat of filler.. Should i apply a special filler over the bear metal to seal the welds? or should i apply a primer of some sort over the metal before the filler is applied if so what type of primer? epoxy? etch? also what type of filler would be best to be used over the primer?
easy sand? etc?

all help is appreciated

[alllfa]

can someone please help me??

[180OUT]

Quote:

fellow bb members. Please excuse my ignorance but i am half way through the restoration of my car, i have removed the rust in sections and welded new metal on top of my repairs. I will now require a light coat of filler.. Should i apply a special filler over the bear metal to seal the welds? or should i apply a primer of some sort over the metal before the filler is applied if so what type of primer? epoxy? etch? also what type of filler would be best to be used over the primer? easy sand? etc? all help is appreciated

[Joe Papa Sr]

Quote:

Originally Posted by 180OUT I can suggest that you visit your local Borders book store and look in the car section. There are a number of excellent books on car painting. Also, it certainly wouldn't hurt to make friends with your local automotive paint store. The people who work there often know quite a lot about their products. I've usually found their advice to be good.

[74veloce]

Here's my two cents on the filler issue. I don't believe in putting any filler over the top of a primer, whether epoxy or not. The rule of thumb to always follow is that your final project is only as strong as your weakest bond. Primers adhere excellently to filler and filler to metal, but not so much primer to metal.
Of course, I don't apply the filler directly over the top of the metal either. As EdP touched on, it's generally best to do an "etch" first. This is typically a phosphoric acid based solution and is also called "rust-mort" or "rust converter", but is NOT navel jelly! Once the metal is bare and clean I take a small amount of etch on a rag (wear gloves for pete's sake, this is acid!! ) and wipe down the surface of the metal. Rust is oxidized metal; as such as soon as you expose the metal to oxygen it will start oxidizing. Whether or not you can see it, if the metal has been exposed for ANY amount of time it will have oxidation. The etch stops the oxidation cold and keeps any futher oxidation from happening. The etch will also leave a slight film on the surface which can be removed with a quick wipe down of wax and grease remover. A gallon of good etch is about $30 at your local paint store and I feel it is an essential item for anybody doing body work.

[PSk]

Quote:

Originally Posted by 180OUT Generally, the filler goes on first, then the primer.

[180OUT]

Quote:

Originally Posted by PSk This is not correct, I believe. Metal needs to be sealed first, otherwise it will sweat and rust will start under filler. Please ask Daron (akitaman) this question. Pete