Very Unique Bondo Problem! Paint Screwing it up? - Page 2

Altimat · 12-08-2004, 08:27 AM

You want a sandable "filler" primer, and you do not need a sealer. The sandable primer serves this function, and is used in this way over fillers (bondo) all the time. A filler primer will build thickness, which is what you want. Just make sure to allow sufficient time between coats. Think of primer as a thinner sprayable filler.

Grayscale · 12-08-2004, 07:21 PM

Ahh too late I got sandable primer, not sandable filler primer. The only difference the guy said was that it was that the filler stuff is a bit more thick. It was orange though. And that would look bad if I got a scratch, so I went with the black stuff. Yeah and the surface is really hard again! So if I have time I will sand on the paint a bit, re-bondo, primer it, and paint on it weeee

Unless you guys think the paint isn't too slick and I could just apply bondo directly on it? I bet it will adhere. Let me know! Thanks!

Altimat · 12-08-2004, 09:33 PM

Don't bondo over paint. Its best if bondo is just applied over the base material.

Grayscale · 12-13-2004, 05:24 PM

What about bondoing over primer if I find a little dip or a mistake? I haven't done it yet, haven't had time but just wanting to know for future reference. Also, I did do a little bondoing over half paint/half bondo ( I couldn't sand it all down good, it would just get stuck in the sandpaper ), and it seems fine.

futuresweets10 · 01-04-2005, 10:37 PM

RANT TIME!!! If you used body filler at a thickness greater then 1/8in then I would reccomend removeing it and starting over if you want it to last. Also, you are not supposed to be able to paint right over body filler. It must be primed before you cant paint over it. I also do not reccomend useing that bulldog stuff on body filler, only on bare plastic, however, if you clean and prep bare plastic properly you wont need that stuff. good luck

Grayscale · 01-05-2005, 12:15 PM

Quote: Originally Posted by futuresweets10

RANT TIME!!! If you used body filler at a thickness greater then 1/8in then I would reccomend removeing it and starting over if you want it to last. Also, you are not supposed to be able to paint right over body filler. It must be primed before you cant paint over it. I also do not reccomend useing that bulldog stuff on body filler, only on bare plastic, however, if you clean and prep bare plastic properly you wont need that stuff. good luck

yeah the bulldog stuff is bad. i've learned the best thing to do is just primer it real well and then you can paint on it just fine. its going in my dash man, its not likes its on the exterior of the car and gonna be under lots of stress. i've had my old custom fabricated dash for a long long time and it is just fine.

CustomZ02 · 01-07-2005, 02:04 PM

I did my dash in 4 hours :/ Didnt have any problems with the bondo. I had it all bondo'd and painted and installed in 4hrs and Im livin up here in Reno, NV and the temps were like 50F. I think if the bondo crumbles it means that it wasnt mixed too well or not enough hardner was added. If you get them mixin spatulas for bondo it has a pink color to it. When you mix ur bondo it should match to color of the spatula. After that I apply it and let it sit for about 30mins then start sanding it. I guess from the friction of sanding the bondo heats up and cures faster and by the time im done sanding its has hard as a rock. Then I lay some primer down and resand and look for pits and dips then refill those in. let em sit for about 10 mins and sand them down again. Then add a final coat of primer let dry and paint. After the paint dries I do a wetsand on it to get it really smooth and then add another coat. After the last coat dries I do a final wetsand and then dry it off and add some clear coat. Like I said I did mine in 4hrs with not a problem, any problems with crumbling or bondo not drying I believe has to do with the not having enough hardner or a bad mixture.

Grayscale · 01-09-2005, 11:11 AM

Quote: Originally Posted by CustomZ02

I did my dash in 4 hours :/ Didnt have any problems with the bondo. I had it all bondo'd and painted and installed in 4hrs and Im livin up here in Reno, NV and the temps were like 50F. I think if the bondo crumbles it means that it wasnt mixed too well or not enough hardner was added. If you get them mixin spatulas for bondo it has a pink color to it. When you mix ur bondo it should match to color of the spatula. After that I apply it and let it sit for about 30mins then start sanding it. I guess from the friction of sanding the bondo heats up and cures faster and by the time im done sanding its has hard as a rock. Then I lay some primer down and resand and look for pits and dips then refill those in. let em sit for about 10 mins and sand them down again. Then add a final coat of primer let dry and paint. After the paint dries I do a wetsand on it to get it really smooth and then add another coat. After the last coat dries I do a final wetsand and then dry it off and add some clear coat. Like I said I did mine in 4hrs with not a problem, any problems with crumbling or bondo not drying I believe has to do with the not having enough hardner or a bad mixture.

Hmmm. The problem occurs when I have too much hardener I've found. The way I get the perfect mixture now is to take a blob of bondo, about the same depth as what comes out of the hardener tube, divide in 4ths, then divide the 4th in half then divide again. I end up getting about 10% hardener in really. That is about the perfect amount I've found. Sometimes a little less works fine too. But I've gotten all the kinks worked out. The primer has gone on great on the stuff I've been working on. I haven't painted over the primer yet, but I hope that goes well.

So you're saying you were working with bondo that was 50 degrees? I've been trying to stay in a pretty warm place (at least 60-65 degrees), but if thats not such a big deal I may not worry about it so much.

EBFoxbat · 01-09-2005, 11:22 AM

So what would I use to fill in small gaps in a fiberglass shell that could easily be primed and painted? Sorry to hijack the thread.

Grayscale · 01-09-2005, 11:34 AM

Quote: Originally Posted by EBFoxbat

So what would I use to fill in small gaps in a fiberglass shell that could easily be primed and painted? Sorry to hijack the thread.

it's cool, since my problem is already fixed i'll forgive you

. Well, I would use bondo (go figure). Don't use the glazing and spot putty. Somehow when I used that it like melted my primer and I had to peel/scrape with my fingernail all of the primer off that I had put the spot putty stuff over. Dont know why it did that. I mixed it exactly as the instructions said. Bondo's not so bad to work with tho, really. I think a lot of people touch up fiberglass work with bondo.