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I need help and suggestions with underbody

widowmaker77

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Oct 11, 2007
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Fellows I’m building my old 66 to be a weekend driver. I’m wanting to blast the underside and paint and undercoat it. My problem is I’m currently running out of time and money to do everything that needs done to it. I bought a blasting pot from tractor supply and have had good results with it so far blasting a Dana 44. So I’m planning on doing the blasting myself over the upcoming holidays. My plan is this, blast underside and engine bay then coat with ospho but I’m stuck at the next step. Is there anything out there I can paint the underside with that will seal it against rust while I drive it, then when I get more time and money do raptor liner? Or is it best to go ahead and do all the primer, paint and raptor All together before any off-road use?? What has everyone used? Any help will be appreciated greatly. I live in south Alabama so road salt is not a concern for me just mud and dirt.
 

englewoodcowboy

Lick Creek Restorations
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Jul 25, 2010
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Best to do it all at once. Ospho wont be needed if you are going to bare metal and will save a step. Best option is to get a DTM (Direct To Metal) epoxy primer and paint everything with that once bare. I will have a redcoat window that you will want to follow for top coating it otherwise if you go beyond that window it will need to be scuffed. Blast, seam seal, epoxy seal paint or raptor is the best order.
 
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widowmaker77

widowmaker77

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Thanks for the input! So if I blast the underside, your saying I don’t need to treat the rusty panels with ospho and just go straight to seam sealer and then a bare metal epoxy primer? Do you have one you would suggest? I’ve been looking at the upol anti corrosive 2k epoxy primer but I don’t see where it says straight to bare metal. Any experience with this primer?
 

AZ73

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If you use something like KBS rustseal you won't need to raptorline it or even paint it over if you chose a color they offer. If you decide to go that route I can send you a 15% off link they sent me.
 

jmangi62

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The epoxy primer is your best choice, then whatever you want after that, paint, liner, whatever. As far as brand of epoxy, all you need is a good quality automotive grade for example, Valspar, ppg, House of Colors etc. IIRC I used House of Colors epoxy primer on my rig and couldn't be happier. Just my .02 ;D
 
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widowmaker77

widowmaker77

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If you use something like KBS rustseal you won't need to raptorline it or even paint it unless you want a color other than black. If you decide to go that route I can send you a 15% off link they sent me.

I’m open to all suggestions. I’m new to paint and body stuff but I’m trying to learn and I want to do it all myself. The underside color doesn’t much matter to me in fact I kinda prefer black. This bronco will be used but with that said I still want it to be nice and look good. I just want to treat what rust is in the rear quarters and tail light section and seal it. I would prefer to raptor liner it but time and money is running out. I need to get it going and usable.
 

bronkenn

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POR15. Follow their instructions and it will last a long time. Very durable and easy to apply. Sand blast, cleaner, metal prep and paint with a brush. Weekend project. I have been using this for 20 years and it has held up great. KBS is basically the same stuff.
 

markw

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I'd stay away from the Raptor, et al. Holds dirt and it's a real pain if other repairs need to be done down the road.
 
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widowmaker77

widowmaker77

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POR15. Follow their instructions and it will last a long time. Very durable and easy to apply. Sand blast, cleaner, metal prep and paint with a brush. Weekend project. I have been using this for 20 years and it has held up great. KBS is basically the same stuff.

Thank you for the info! Like I said before I’m new to all this so please Excuse the dumb questions. I’ve read A good bit about por15. If I blast the panels and treat them with the ospho will the por15 Stick to it since the rust will be gone?
 

68Broncoz

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Raptor makes a primer that they recommend under the raptor and it states can be painted over light rust
 

englewoodcowboy

Lick Creek Restorations
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Thanks for the input! So if I blast the underside, your saying I don’t need to treat the rusty panels with ospho and just go straight to seam sealer and then a bare metal epoxy primer? Do you have one you would suggest? I’ve been looking at the upol anti corrosive 2k epoxy primer but I don’t see where it says straight to bare metal. Any experience with this primer?

If you are blasting the rust off then no, if you aim to paint over rust as some others have suggested, we have used KBS with great results in the past. To try and get the best bang for the buck is the fewer steps you have to do the better. Ospho when you apply it needs to cure then you need to sand it as it will create a film that will cause paint to release etc. As for finish underneath, I like raptor as it creates a very durable easy to repair under layer that is also easy to clean. The texture of it hides blemishes etc. as well as the thickness it can be applied provides some sound proofing qualities over paint. It all comes down to your end result you want to achieve.
 

AZ73

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Por 15 and KBS are similar, but when I did the research, I ended up deciding on KBS. Yes, other epoxies are good too, but both POR and KBS are water cured, and because of their chemistry, they end up with more mils of thickness when they're dry. Surface preparation is important for any coating, but with regular epoxy, the base has to be almost perfect. POR is a little more forgiving, and KBS is a lot more forgiving. Any surface that's media blasted will work well with epoxy, POR, or KBS. If you need to get back to the metal in the future, KBS has to sanded for a while or blasted again. There are slight differences between these three, so I would recommend looking at things in your specific situation. POR and KBS require specific temps to apply. General epoxy can be controlled with thinner to adjust for wider ranges. POR and KBS, being water cured, are DEADLY without the correct respirator. You'll need a P100 like this to spray it (and I put another fast replaceable particle filter on top of these and swap it out regularly), but they actually both brush on nicely with a roller or brush:

https://www.amazon.com/gp/product/B00AEFCKKY/ref=ppx_yo_dt_b_asin_title_o09_s00?ie=UTF8&psc=1

Both of them will stay on forever whatever they touch, so if you get some on your skin, it'll be there until you skin grows out. It'll never come off your clothes. I also use cheap ($9.99 on sale) Harbor freight sprayers and just toss them when I'm done. Easier than cleaning this stuff off them.

So really it's all about the prep work, and the conditions you are doing your work in. That is probably the best way to make your decision. Good luck!
 
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widowmaker77

widowmaker77

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If you are blasting the rust off then no, if you aim to paint over rust as some others have suggested, we have used KBS with great results in the past. To try and get the best bang for the buck is the fewer steps you have to do the better. Ospho when you apply it needs to cure then you need to sand it as it will create a film that will cause paint to release etc. As for finish underneath, I like raptor as it creates a very durable easy to repair under layer that is also easy to clean. The texture of it hides blemishes etc. as well as the thickness it can be applied provides some sound proofing qualities over paint. It all comes down to your end result you want to achieve.

Ok great! Let me ask y’all this. If I blast, treat with por15 metal prep then do the por15 paint would I be able to go back let’s say a year or two in the future and apply raptor liner over it? If I decide I really want the raptor liner underneath. I understand it’s best to do everything all at the same time but all of that isn’t doable for me right now.
 

hyghlndr

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For good paint for the buck Rustoleum Professional Grade (Home Depot or Lowes in a gallon) or Tractor Supply's Tractor and Implement paint. Both good choices on a budget.
 

Revelation

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Being a 66 if you ever wanted to do a stock resto on it you would kick yourself for using any bedliner.
 

englewoodcowboy

Lick Creek Restorations
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Ok great! Let me ask y’all this. If I blast, treat with por15 metal prep then do the por15 paint would I be able to go back let’s say a year or two in the future and apply raptor liner over it? If I decide I really want the raptor liner underneath. I understand it’s best to do everything all at the same time but all of that isn’t doable for me right now.

You should be able to, just be sure you read the products info is all. Most will require a good scuff for adhesion but if the products are dissimilar you may need to add a link coat between them like an epoxy or some of the products like KBS may simply require a fresh application of that in between whatever you top coat it with for best performance. All of the data should be on the products to determine.
 
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widowmaker77

widowmaker77

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For good paint for the buck Rustoleum Professional Grade (Home Depot or Lowes in a gallon) or Tractor Supply's Tractor and Implement paint. Both good choices on a budget.

Thank you sir. I might have to go this route for the time being. Three in college and Christmas time has taken a toll on my budget. Lol
 
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