Topic: tips and trick with bondo

[Russ]

Hey guys it is me again needing help what is new. I am trying to smooth in my quarters and kind of a newbie with Bondo and need some tips on how much how to put it on there and what to and not to use when taking it off. I have a body file and a da and of course my hand. I am in a bind and any help would be an improvement. I am hoping to really get some help, Thanks. STANG OUT

[racedraper]

you need a good sanding block. something that can match the contours of the body. Dont mind that your car has bondo, cause all of you high end cars apply a thin coat so that it can have a perfect look. also there is a primer called slicksand, its super thick when applied and fills in any bad spots.

this is a link for the type you need for sanding
http://images.google.com/imgres?imgurl=http://www.route66supply.com/store/media/afsbanner2.jpg&imgrefurl=http://www.route66supply.com/store/page50.html&h=159&w=264&sz=19&hl=en&start=16&um=1&tbnid=0N5YqTZrr8wS0M:&tbnh=67&tbnw=112&prev=/images%3Fq%3Dcar%2Bsanding%2Bblocks%26svnum%3D10%26um%3D1%26hl%3Den%26client%3Dfirefox-a%26rls%3Dorg.mozilla:en-US:official%26hs%3DE8S

[Thierry]

Don't use bondo over rust. I did it once and the rust came back in less than a year even with most of the rust sanded off. Bondo has to be applied on solid metal, free of dust and grease. You can clean the panel with paint thinner. The thickness of the bondo has to be less than a 1/4 inch or it will crack.
Hotrod magazine published an article about it and said that Metal putty has superior qualities than regular bondo. It can be drilled and tapped and paint adheres to it better.
I will try to find the article and let you know if there is more about it.

[KarenCaren]

I got this from a website. I hope it helps.

Bondo Mixing Tip:  I like to mix my bondo on a piece of flat glass. I use an old side window from my truck. It will not absorb any of the bondo (don't use cardboard) and is easy to clean. I put a ball of bondo on the glass and a proper length of the hardener next to it. I use two of the yellow spreaders about 4 inches long to mix it. Use one and then use the other to wipe it off the first back onto the glass until mixed. After putting the bondo on the car I scrape any left over off of the spreaders and the glass with a 1" wood chisel. Then I take some paint thinner on a paper towel and finish cleaning the glass, spreaders, and chisel. Believe me if you keep all of this clean you will do a better job. If not you will get chunks of old bondo in the new on the car and if your spreaders aren't clean and straight edged you will drag grooves in the new bondo as you spread. (Note: these type of tips are going to make this longer, but I don't see this stuff mentioned in the books and it can really help speed the process up and make it less frustrating, so bear with me or skip over my tips).

[rmodel65]

a great mixing board for filler is an alum sign(i dont condone the taking of street signs) when it gets built up you can either bend it to pop it off or take the sander to knock it down

a "cheese grater" work great to get it all knocked down before sanding, you do this before it hardens but not while its still wet

i normally use 80 grit to start then 220 then 320 then i prime block with 400 then 800grit

[Soaring]

The point is that bondo type fillers should be used sparingly.  If you have to fill a hole with it, you are using the wrong product.  It is to be applied in a very thin bed, then sanded down as Stephen has described.  I use a wide putty knife to apply it, then go back several times with the putty knife to make sure that only the slightest indentions in the metal are filled with it.  When you are through sanding and have it tapered to nothing, then use a self etching primer and put color to it asap.  Primer will absorb moisture, so do not leave it out in the rain or wash the car before color. 

[rmodel65]

dont wanna use a etch primer on filler only bare metal not even over paint, over the filler you need to use either an epoxy or a 2k sandable primer

[Soaring]

I just now read where I wrote etching primer instead of epoxy.  That was a slip....sorry.  Musta' had too much California red that night. 

[Russ]

  okay guys, I have built alot of hot rods with my father but never spent time watching or working with bondo. As you know I had to get my quarters on and I used Evercoat lightweight, not bondo, but is suppose to be close. Anyways, I found that I put it on and started sanded and took it all right back off.

 I kept trying to put it on thin and build it up but those welds were big and not sure if I messed it up or not. Like I said ew to this and really trying to take my time. The car was done a while ago and is in the garage everyday so I am not trying to rush anything. I also will have patch panels put on them time soon I am going to put on pics of what happened, from the weld to first coat, all the way to the primer. I will try to use different pics than on my other post. I also had to build up the side from where the mach one sign would go to the front of the rear quarter. I know Thierry said you don't want to use more than 1/4 and I am afraid that I might have use more than that guys take a look at the pics and let a brother know.

If I need to fix it I can like I said it only has primer and really itsn't done now anyways, but about 85% complete. I will still have to strip the primer off and touch it up before I seal it and throw the paint to her. I think I did a good job but let me know and remember I am in the army I have tough skin,lol. I will cry in my bathroom.



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[Russ]

here is another, and remember I can spray primer to save my @$$

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[Soaring]

Russ, I am not a body expert, but I have seen where other guys had to drill holes in the metal, then press the body filler into the holes and spread it on the flat surface.  They were then able to sand it down to almost bare metal, but still have the bondo stick so they could get it paper thin.  Stephen will be along shortly to either correct me or confirm.   

[Russ]

Thanks for getting back with me that is hopefully something that might help me. I am just trying to get the art of spreading down and I know I cannot get any worse.

[Soaring]

See if this tip helps you any.  Instead of drilling holes, you might want to check your metal preparation. I didn't know about the putty after the bondo was sanded down either.   Looks like good stuff.  (Where are you Stephen?   )
http://www.creativemods.com/guides/guide_view.php?url=bondo_case_body_work

[Russ]

great link, you are the man

[Thierry]

[attachment deleted by admin]

While doing some maintenance on the board today I accidentally deleted some photos. I stopped the process as soon as I realized my mistake so I don't think many of them are gone but if you see this message, I am the one to blame 

[Russ]

hey brother it is all good man, you are still the best canadian friend I have,lol.

[rmodel65]

Russ, I am not a body expert, but I have seen where other guys had to drill holes in the metal, then press the body filler into the holes and spread it on the flat surface.  They were then able to sand it down to almost bare metal, but still have the bondo stick so they could get it paper thin.  Stephen will be along shortly to either correct me or confirm.   

they used to do that back in the day glen with the holes, you would drill a hole put a screw in it and pull it with a slide hammer to it was near flush. technically you need to weld up those holes afterward. if you don't weld the holes up then the filler wiped over the holes will quickly absorb water leading to rust. (if you don't have a welder some guys use fiberglass matt and resin to fill small holes, but you have to tap them slightly lower to use it.)

when wiping filler you ideally want a bare metal surface with 36-80 grit scratches. what i do is wipe a thin layer of filler on spread it all around, then the 2nd, 3rd etc. i use a cheese grater to knock down the high spots in the filler while its drying(not wet just where its tacky and slightly solid) then i normally use 80 grit, if i need to wipe it again i use filler. then repeat the process.
then if it needs it i use the spot filler, i don't use that 1k(lacquer based) spot putty. I use a 2 part finishing glaze it is  just like regular filler but a lot thinner. i go over everything with 220 then prime, then block with 320,if its needed i prime once more then block with 320, then 600-800 for sealer then paint normally if i need the second coat of primer i lightly spray a guide coat on the panel(contrasting color shows what you might miss with the feelings from your hands.) after the second coat this will ensure i am able to "see" if its straight this really helps out when your new to getting the panel straight.


also one of the best sanding blocks you can use is the paint mixing sticks long flexible and about 1cent

[Soaring]

Paint mixing stick, huh?  They are free at Ace.     Yeah, after I wrote that about drilling holes, I remembered you had to weld them shut or they would rust.  So, I guess the best thing to do is get down to bare metal and scuff it up some so the bondo sticks.  I absolutely hate body work.  It is very time consuming and is a tremendous amount of labor.  I envy anybody who does it well. 

[Russ]

Well I hope to be going home soon and will try it. I will end up trying to do to much and forget something. I only get  a few weeks at a time and live and the garage while I am there. Keep it comming thanks guys

[Soaring]

Russ,
Here is another link for you.  These guys are professional body guys.
Just some more information to help you get that Mach standing tall.  
www.autobody101.com