What first, bondo or epoxy primer on bear metal

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What first, bondo or epoxy primer on bear metal

Postby tomb22 » Tue May 16, 2017 2:50 pm

Having my car media blasted and I'm questioning what I should do first to the bare metal. Do the bondo or epoxy primer. Ive bought Nason epoxy primer and was thinking of shooting the whole car first. I do have quit a bit of bondoing to do also.
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Re: What first, bondo or epoxy primer on bear metal

Postby Loner » Tue May 16, 2017 3:04 pm

I put the bondo on first,really don't think it matters as long as you scuff it good with at least 80 grit. If it is going to take you a few months to get it done spray the epoxy on the car, then you won't have to worry about it rusting.

Matt
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Re: What first, bondo or epoxy primer on bear metal

Postby Lou's Comet » Tue May 16, 2017 6:33 pm

Epoxy primer first, then bondo.

Never used "Nason" epoxy. Does it have a window of time where you can spray over it or spread your bondo without sanding it, the epoxy?

Th epoxy primers (PPG) I use have a window of time where you can apply the bondo or spray your primer/surfacer over it without sanding the epoxy.

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Re: What first, bondo or epoxy primer on bear metal

Postby tomb22 » Tue May 16, 2017 9:28 pm

Lou's Comet wrote:Epoxy primer first, then bondo.

Never used "Nason" epoxy. Does it have a window of time where you can spray over it or spread your bondo without sanding it, the epoxy?

Th epoxy primers (PPG) I use have a window of time where you can apply the bondo or spray your primer/surfacer over it without sanding the epoxy.

Lou


Nason is made by Dupont and you got 24 hrs to topcoat it without sanding.
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Re: What first, bondo or epoxy primer on bear metal

Postby Lou's Comet » Wed May 17, 2017 5:43 pm

Wow not much of a window for epoxy. But any how in my opinion you definitely want to epoxy first. After it is blasted I would sand it with 80 on a da, then put two good coats of epoxy on it. You also want to spray it thru a gun with a larger tip 1.5-1.7 to get good coverage.

Been doing bondo over epoxy for over 20 years with great success.

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Re: What first, bondo or epoxy primer on bear metal

Postby Loner » Wed May 17, 2017 6:46 pm

So Lou do you straighten out all the dents and do all your heat shrinking before the epoxy? Or do you just grind the epoxy off in those spots that need to have heat shrinking done to them?


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Re: What first, bondo or epoxy primer on bear metal

Postby Lou's Comet » Wed May 17, 2017 6:59 pm

I usually do one panel at a time.
I take it down to bare metal, do all the metal work first, then 2 coats epoxy, then filler where needed and re epoxy after bondo work is done. Then within the window I apply my surfacer.

I don't see why you couldn't epoxy the whole car and then sand off the panel that needs work, and when done with the metal work apply the epoxy again then the bondo.

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Re: What first, bondo or epoxy primer on bear metal

Postby tomb22 » Wed May 17, 2017 7:47 pm

Lou's Comet wrote:Wow not much of a window for epoxy. But any how in my opinion you definitely want to epoxy first. After it is blasted I would sand it with 80 on a da, then put two good coats of epoxy on it. You also want to spray it thru a gun with a larger tip 1.5-1.7 to get good coverage.

Been doing bondo over epoxy for over 20 years with great success.

Lou


Thanks for the advice Lou. I'm interested in what type of epoxy you use to have a longer window
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Re: What first, bondo or epoxy primer on bear metal

Postby Loner » Wed May 17, 2017 8:12 pm

Lou's Comet wrote:I usually do one panel at a time.
I take it down to bare metal, do all the metal work first, then 2 coats epoxy, then filler where needed and re epoxy after bondo work is done. Then within the window I apply my surfacer.

I don't see why you couldn't epoxy the whole car and then sand off the panel that needs work, and when done with the metal work apply the epoxy again then the bondo.

Lou


Lou is there a reason to have the epoxy under the bondo? Seems like extra work doing it that way but you might know something I don't.
I also do one panel at a time makes the job feel smaller.

Thanks, Matt
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Re: What first, bondo or epoxy primer on bear metal

Postby Lou's Comet » Wed May 17, 2017 8:37 pm

tomb22 wrote:Thanks for the advice Lou. I'm interested in what type of epoxy you use to have a longer window


I use PPG products. I have used their high end DPLF epoxy which is pricey but IMO great stuff. The window is 7 days, I use their Omni line epoxy primer more lately because of price, less than half the price. the window on the Omni (I think it is MP170) is 3 days

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Re: What first, bondo or epoxy primer on bear metal

Postby Lou's Comet » Wed May 17, 2017 8:56 pm

Loner wrote:
Lou is there a reason to have the epoxy under the bondo? Seems like extra work doing it that way but you might know something I don't.
I also do one panel at a time makes the job feel smaller.

Thanks, Matt


Better corrosion protection.

The first car I did in epoxy was in 92. Took the whole car down to bare metal, did the metal work and put in epoxy. The owner run out of money.car went outside for over a year. Brought car back in shop to finish no rust anywhere. Sanded car back down to metal just to be sure. Did the epoxy again and finished car. The guy took care of it, but then got married, kids, and started doing taxidermy in his garage so car went outside and sat in yard for 3/4 years. Decided to sell the car and brought it to me to clean up for sale. No rust, no bubbling of filler after buffing car looked like it did after painting.

A better test was 2 trucks I did. 2 of my friends have a pressure wash company. Everything gets wet,lol plus chemicals.

I did both of their pickups, guessing 2006, they needed bed arches, cab corners, typical pa rust areas. One I did without the epoxy the other one I used epoxy. About 2014 I had to do the bed arches a second time on the one without epoxy, bubbling and some rust thru. The one with epoxy nothing, no bubbling, no rust, arches still looked great.

Now I did the arches exactly the same on both trucks. Cut out all rusty metal, weld thru prime, sandblasted the welds after grinding smooth, etc. the one without epoxy lasted about 6/7 years the one with epoxy still looks good. It is sitting beside their shop with a rusted out frame, but the bed is still nice and solid.

I now always use epoxy before the filler on everything unless it is a cheaper job.


Doing one panel at a time just makes it more manageable for me and as you say seems like a smaller job,
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Re: What first, bondo or epoxy primer on bear metal

Postby Loner » Wed May 17, 2017 9:56 pm

Thanks for taking the time posting a answer for me Lou. I always want to do the best job I can even if it takes longer. Going to read up on the best way for the products I use.

Thanks again,Matt
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Re: What first, bondo or epoxy primer on bear metal

Postby captian_napalm » Thu Jun 29, 2017 7:12 pm

Loner wrote:I put the bondo on first,really don't think it matters as long as you scuff it good with at least 80 grit. If it is going to take you a few months to get it done spray the epoxy on the car, then you won't have to worry about it rusting.

Matt

STOP....... don't use bondo it will suck moisture out of the air like a sponge... use all metal. it can be tapped.
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Re: What first, bondo or epoxy primer on bear metal

Postby Loner » Thu Jun 29, 2017 7:18 pm

captian_napalm wrote:
Loner wrote:I put the bondo on first,really don't think it matters as long as you scuff it good with at least 80 grit. If it is going to take you a few months to get it done spray the epoxy on the car, then you won't have to worry about it rusting.

Matt

STOP....... don't use bondo it will suck moisture out of the air like a sponge... use all metal. it can be tapped.


Toooo late :shock: :shock:
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Re: What first, bondo or epoxy primer on bear metal

Postby Lou's Comet » Sun Jul 09, 2017 4:42 pm

Loner wrote:
captian_napalm wrote:
Loner wrote:I put the bondo on first,really don't think it matters as long as you scuff it good with at least 80 grit. If it is going to take you a few months to get it done spray the epoxy on the car, then you won't have to worry about it rusting.

Matt

STOP....... don't use bondo it will suck moisture out of the air like a sponge... use all metal. it can be tapped.


Toooo late :shock: :shock:


You'll be fine.

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