To Undercoat or Not to Undercoat....that is the question
October 25th, 2010, 04:18 PM
#1
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To Undercoat or Not to Undercoat....that is the question
I'd like your opinions on this one. My 70W is a beater to be sure. My intent for now is to just getting it running so I can use it and resist the urge to start restoring it....but everytime I go near it that urge gets harder and harder to resist.
I just spent about an hour underneath the beast and she's ugly as all hell under there. But what I did notice is that the underside was HEAVILY undercoated back in the day. And although it's really ugly now....I'm rather impressed at how it preserved the frame and body.
Because I plan to use my W as a daily driver (especially AFTER it's restored) I'm starting to think the right thing to do would be to undercoat the body and frame after they are restored and still seperated. Now when I do the resto I'm not planning on putting all the individual stickers on the underside parts or making sure the exact shade of semi-gloss black is on each part.......I want it nice.......but functional. Most important I want it to LAST.
I could certainly forego the undercoating.....and then cringe everytime I hit a puddle or drive it in the snow. But once you undercoat you're committed.....no turning back and hopefully no regrets.
So what do you guys think????
regards,
bob
I just spent about an hour underneath the beast and she's ugly as all hell under there. But what I did notice is that the underside was HEAVILY undercoated back in the day. And although it's really ugly now....I'm rather impressed at how it preserved the frame and body.
Because I plan to use my W as a daily driver (especially AFTER it's restored) I'm starting to think the right thing to do would be to undercoat the body and frame after they are restored and still seperated. Now when I do the resto I'm not planning on putting all the individual stickers on the underside parts or making sure the exact shade of semi-gloss black is on each part.......I want it nice.......but functional. Most important I want it to LAST.
I could certainly forego the undercoating.....and then cringe everytime I hit a puddle or drive it in the snow. But once you undercoat you're committed.....no turning back and hopefully no regrets.
So what do you guys think????
regards,
bob
October 25th, 2010, 04:25 PM
#2
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I would deff do some type of undercoat! I have a 70 cutlass s, which I did the whole undercarrage in por-15. I wanted something that was tough and would last. I think the rubberized undercoating is not going to last.
And also por-15 stops rust!
And also por-15 stops rust!
October 25th, 2010, 04:39 PM
#3
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Hi Rennoc442,
I'm a fan of POR15....I've used it on lots of things with good results. Just have to make sure it's topcoated or the UV rays will eat it up.
I'd have to disagree with you on the rubberized undercoating though. That's what's on the car now....and it sure did last. Not to mention being impossible to remove......but that question is for a later post.
Ok.......we have one vote for undercoating (of some sort).
thanks,
bob
I'm a fan of POR15....I've used it on lots of things with good results. Just have to make sure it's topcoated or the UV rays will eat it up.
I'd have to disagree with you on the rubberized undercoating though. That's what's on the car now....and it sure did last. Not to mention being impossible to remove......but that question is for a later post.
Ok.......we have one vote for undercoating (of some sort).
thanks,
bob
November 23rd, 2010, 09:43 AM
#5
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Gunk Engine Degreaser removes the regular rubberized undercoating, spray heavy and let it soak. You can go over it with a plastic scraper, spray some more, scrape, you get the idea, but it does come off, and doesn't booger the area like a wire wheel or something would. May take a few times, but it works.
I too am a POR-15 fan, am in the middle of doing an entire car now (the 72 clone), and on the underside, you don't have to worry about UV! I still undercoat though.
If you want a real tough solution, use truck bed liner on the underside over the POR-15.
Driver = undercoat . Especially if you plan on keeping the car. At least that's my opinion. I do the frame rails too...
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I too am a POR-15 fan, am in the middle of doing an entire car now (the 72 clone), and on the underside, you don't have to worry about UV! I still undercoat though.
If you want a real tough solution, use truck bed liner on the underside over the POR-15.
Driver = undercoat . Especially if you plan on keeping the car. At least that's my opinion. I do the frame rails too...
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November 23rd, 2010, 05:34 PM
#7
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rubberized undercoating gets my vote and it last a very long time. It has always been put on my cars and dads cars as in addition to what was on the car new.
We live in the NE and the rubberized undercoating is very cost effective / bang for the buck. it also deadens road noise.
We live in the NE and the rubberized undercoating is very cost effective / bang for the buck. it also deadens road noise.
November 24th, 2010, 04:11 AM
#10
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This is good info lifted from another post like yours.
Here we go.
POR-15 isn't really a painting paint, it's a rust sealer coating meant to paint over active rust (seen rust come right back through it many times though?) it isn't meant for general painting, peels right off without a UV protectant (and with it anyway), doesn't adhere to non rusted surfaces well, funky finish and color, very expensive.
I know how to prep for paint and have never had anything but problems with the stuff, seen guys have to strip it all off their frames and underbodies after it goes south several times, they just wouldn't listen.
The best thing is not to be lazy and get all the rust off and do it right to begin with.
I learned my lesson a long time ago along and won't let the stuff near my cars along with countless other car guys, I actually hate the stuff.
If you have to use rust paint on your farm implements the Eastwood stuff is way better and you don't need special very-very expensive thinners to spray it and clean your equipment.
To each their own, go ahead and use POR-15, weasel leavings, wombat fluid, whatever... a person has the right to screw up their own car all they want.
If you prep the surface correctly all you need a is a good semi-gloss lacquer and it will last nearly forever with proper maintenace and be factory correct, look ten times better too. Why does everone think they need some kind of bulletproof forever underbody coating? Where and what do you plan on doing with the car to have it be that susceptible to rust? I did the underbody and engine compartment of my GTO 15 years ago with Eastwood underhood black which is the correct gloss % and black shade and it looks like I did them yesterday, and I drive the car plenty. The underbodies and frames really don't take that much abuse unless you're driving down gravel roads all the time.
POR-15 isn't really a painting paint, it's a rust sealer coating meant to paint over active rust (seen rust come right back through it many times though?) it isn't meant for general painting, peels right off without a UV protectant (and with it anyway), doesn't adhere to non rusted surfaces well, funky finish and color, very expensive.
I know how to prep for paint and have never had anything but problems with the stuff, seen guys have to strip it all off their frames and underbodies after it goes south several times, they just wouldn't listen.
The best thing is not to be lazy and get all the rust off and do it right to begin with.
I learned my lesson a long time ago along and won't let the stuff near my cars along with countless other car guys, I actually hate the stuff.
If you have to use rust paint on your farm implements the Eastwood stuff is way better and you don't need special very-very expensive thinners to spray it and clean your equipment.
To each their own, go ahead and use POR-15, weasel leavings, wombat fluid, whatever... a person has the right to screw up their own car all they want.
If you prep the surface correctly all you need a is a good semi-gloss lacquer and it will last nearly forever with proper maintenace and be factory correct, look ten times better too. Why does everone think they need some kind of bulletproof forever underbody coating? Where and what do you plan on doing with the car to have it be that susceptible to rust? I did the underbody and engine compartment of my GTO 15 years ago with Eastwood underhood black which is the correct gloss % and black shade and it looks like I did them yesterday, and I drive the car plenty. The underbodies and frames really don't take that much abuse unless you're driving down gravel roads all the time.
November 24th, 2010, 04:43 AM
#11
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I have used the POR-15 engine enamel and that stuff is as hard as nails. I think I recall reading that the frame enamel is not only hard but UV resistant too so it would hold it's color well. I vote for POR-15. Bluevista has a point about preparation and he is right, if people are using a product in the wrong way or not doing the correct preparation then the product will not work, no matter what name is on the label.
November 24th, 2010, 05:14 AM
#13
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I'm surprised to hear someone had issues with POR-15. All I can think of is that they didn't apply it right, because in my 25 years of using it, whatever it gets on an dries, it never comes off. That stuff was developed for submarine and ship hulls, and it's supposed to even chemically reverse the rust process. If it didn't work, why would people still be using it?
Sure, there are other methods of rust protection, and sure many work very well. Usually people find something that works for them and stick to it, and for me, as well as a number of others, POR-15 works, and I keep using it. There's always going to be nay-sayers for any product, etc, so just means you need to review all the information and make an informative choice for yourself.
As for why you would want to do your floor pan underside with something like POR-15 and a top coat, well, so you don't have to ever worry about it again. I drive my cars all year 'round, and the chemicals used to treat roads, especially in states that use 'salt', is highly corrosive to cars. Salt air at the beach has an affect as well, another reason to 'protect'. And if just 'paint' worked, why then are we doing it now to our cars, and why are floor pans rotted out? Factory painted them, right?
The Cutlass I have came from PA, and it sat in the driveway of a 'little ol' lady' (no kidding) for like 20+ years. The entire car was surface rust, hood, deck lid, tops of the fenders, whole underside, frame, everything. That stuff was painted from the factory, actually I believe e-coated, every part, individually, and it rusted. One rock kicked up on the factory paint will chip it, and expose bare metal, which will rust. All the areas under the car I hit with a wire brush to knock off the scale, marine-clean, and POR-15'd it. Then shot it with undercoating. I've done a number of cars that way, and they still look like when I did them, and have been doing them that way since the early 80s.
POR stands for Paint Over Rust, meaning you don't need to prep it like you would have to with other paints. Shoot, when cars hit the chippers, rusted, that stuff got melted down, and rust was manufactured into the panels! No prep is going to keep that from rusting! Look at Chrysler cars from the day, rotted, and that's because they didn't have the same requirements for the material used when stamping panels. Moisture actually makes POR harder, and the chemicals react to iron oxide, or, rust.
I dunno, like I said, it works for me, and I have a long history with POR, so, I'll keep using it. My intention was to share what my experiences are, the choice is up to everyone individually.
.
Sure, there are other methods of rust protection, and sure many work very well. Usually people find something that works for them and stick to it, and for me, as well as a number of others, POR-15 works, and I keep using it. There's always going to be nay-sayers for any product, etc, so just means you need to review all the information and make an informative choice for yourself.
As for why you would want to do your floor pan underside with something like POR-15 and a top coat, well, so you don't have to ever worry about it again. I drive my cars all year 'round, and the chemicals used to treat roads, especially in states that use 'salt', is highly corrosive to cars. Salt air at the beach has an affect as well, another reason to 'protect'. And if just 'paint' worked, why then are we doing it now to our cars, and why are floor pans rotted out? Factory painted them, right?
The Cutlass I have came from PA, and it sat in the driveway of a 'little ol' lady' (no kidding) for like 20+ years. The entire car was surface rust, hood, deck lid, tops of the fenders, whole underside, frame, everything. That stuff was painted from the factory, actually I believe e-coated, every part, individually, and it rusted. One rock kicked up on the factory paint will chip it, and expose bare metal, which will rust. All the areas under the car I hit with a wire brush to knock off the scale, marine-clean, and POR-15'd it. Then shot it with undercoating. I've done a number of cars that way, and they still look like when I did them, and have been doing them that way since the early 80s.
POR stands for Paint Over Rust, meaning you don't need to prep it like you would have to with other paints. Shoot, when cars hit the chippers, rusted, that stuff got melted down, and rust was manufactured into the panels! No prep is going to keep that from rusting! Look at Chrysler cars from the day, rotted, and that's because they didn't have the same requirements for the material used when stamping panels. Moisture actually makes POR harder, and the chemicals react to iron oxide, or, rust.
I dunno, like I said, it works for me, and I have a long history with POR, so, I'll keep using it. My intention was to share what my experiences are, the choice is up to everyone individually.
.
November 24th, 2010, 02:56 PM
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Ahhhhh.....nothing like a good sensible discussion.....errrr....debate. It's nice we call all have an opinion and not get unruly about it. Can't do that on too many sites these days.
All good info for sure and I appreciate hearing everyone's experiences. I've been using POR-15 or a long time now....mostly on my tractors and things around the farm that tend to rust rapidly when left outside. I have to admit I've never seen POR-15 peel or flake off anything. I've heard people say it doesn't adhere well to newly sandblasted parts that have no surface rust.........but I've done that a million times and it's never come off. I have seen it wear off when left exposed to the sun (UV rays). I guess there's is something to be said for surface prep. I've also seen it fail when applied to flaky rust that wasn't scraped down before application. Seems all the rust must be coated with POR-15 for it really seal the surface.
One thing I think that works for me is I always mist on some top coat immediately after applying the POR-15. I NEVER let it fully dry before top coating.....because nothing sticks to it. If you spray a partial top coat when the POR-15 is still wet it blends into it and gives a good surface for the next shot of topcoat. Now in all the years I've used POR-15 I have never sprayed it from a gun.....always brushed it on. I am looking forward to seeing how it looks when sprayed.
Years ago when POR-15 became popular it's main competitor was something called Corroless (spelling?) that was the color of red primer and available from Eastwood. It was designed for ship hulls I believe. To test both I took a piece of scrap black iron and painted 1/3 with POR-15, 1/3 with Corroless, and left the last third bare. I let it sit outside for a number of years. In the end the Corroless won because the POR-15 wasn't topcoated, got real thin, and finally allowed rust to form..... and the Corroless didn't. Not sure where I'm going with this.....just my experience.
As for why you'd want to make the bottom of your car bulletproof I'd have to agree with HWYSTR455.....I want to do it once and forget about it. Lacquer paint has never been high on my list of paints that are durable....quite the contrary. Just about any chemical will mess it up...so the underside of a car wouldn't be where I'd use it. An Imron or two part epoxy would be a good choice, but I don't know much about them to recommend a specific one.
But Bluevista is right....we're all free to do what we think is right or makes sense. It's just nice that we can share our experiences, be it good or bad, to help the next guy make a better decision.
take care,
bob
All good info for sure and I appreciate hearing everyone's experiences. I've been using POR-15 or a long time now....mostly on my tractors and things around the farm that tend to rust rapidly when left outside. I have to admit I've never seen POR-15 peel or flake off anything. I've heard people say it doesn't adhere well to newly sandblasted parts that have no surface rust.........but I've done that a million times and it's never come off. I have seen it wear off when left exposed to the sun (UV rays). I guess there's is something to be said for surface prep. I've also seen it fail when applied to flaky rust that wasn't scraped down before application. Seems all the rust must be coated with POR-15 for it really seal the surface.
One thing I think that works for me is I always mist on some top coat immediately after applying the POR-15. I NEVER let it fully dry before top coating.....because nothing sticks to it. If you spray a partial top coat when the POR-15 is still wet it blends into it and gives a good surface for the next shot of topcoat. Now in all the years I've used POR-15 I have never sprayed it from a gun.....always brushed it on. I am looking forward to seeing how it looks when sprayed.
Years ago when POR-15 became popular it's main competitor was something called Corroless (spelling?) that was the color of red primer and available from Eastwood. It was designed for ship hulls I believe. To test both I took a piece of scrap black iron and painted 1/3 with POR-15, 1/3 with Corroless, and left the last third bare. I let it sit outside for a number of years. In the end the Corroless won because the POR-15 wasn't topcoated, got real thin, and finally allowed rust to form..... and the Corroless didn't. Not sure where I'm going with this.....just my experience.
As for why you'd want to make the bottom of your car bulletproof I'd have to agree with HWYSTR455.....I want to do it once and forget about it. Lacquer paint has never been high on my list of paints that are durable....quite the contrary. Just about any chemical will mess it up...so the underside of a car wouldn't be where I'd use it. An Imron or two part epoxy would be a good choice, but I don't know much about them to recommend a specific one.
But Bluevista is right....we're all free to do what we think is right or makes sense. It's just nice that we can share our experiences, be it good or bad, to help the next guy make a better decision.
take care,
bob
November 24th, 2010, 04:56 PM
#16
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POR is for painting over rust. It needs rust to adhere to the surface its painted on. For me, I like to get rid of rust not seal it and hope no air gets to it. So its not meant to go on freshly blasted frames and undersides. Its a low budget way to make a surface look good. If one has a scaly frame and they want it to look okay, then by all means go for it.
I have used it, along with fiberglass, to repair the rear window channel of my car. I would not use it on a frame or anywhere else.
November 28th, 2010, 03:14 PM
#17
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Posts: 135
I have to agree with TK-65 on this one. He hit the Nail on the head. Por-15 is a sealer for Rust, but, if all your wanting to do is clean it up a little underneath and drive it, not worry about getting it dirty underneath, then just power wash best you can, let it dry and then blast her with some undercoat. Done deal.
November 28th, 2010, 03:37 PM
#18
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Never needed to paint the frame, but I did paint my trailer with truck bed liner. The cheap stuff too, from Autozone. It sets outside all the time and that stuff has held up better than any paint I have ever used. It has a ruff texture but thats ok with me.
November 28th, 2010, 03:40 PM
#19
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I was on a budget so instead of buying POR-15, i bought a 1 gallon pail of Rustoleum. It works just as well. Just wire brush loose rust scales and clean up the oil spots with brake cleaner, wait till dry and paint over it.
I do use rubberized undercoat and sprayed it all over under the floor pan and truck pan. I also sprayed inside the front and rear door panels. My 70 Cutlass has flowmasters and I have noticed that it quiets the outside noise.
I do use rubberized undercoat and sprayed it all over under the floor pan and truck pan. I also sprayed inside the front and rear door panels. My 70 Cutlass has flowmasters and I have noticed that it quiets the outside noise.
December 7th, 2010, 05:53 AM
#20
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Hey BobB - Eastwood replaced the Correlless product with what they now call their' 'Rust Encapsulator' product, and boast it's a 'paint-over-rust' solution:
http://www.eastwood.com/rust-encapsulator.html
If you're curious about other products, I'm in the middle of doing the clone build now, and am documenting it:
https://classicoldsmobile.com/forums...-new-post.html
I posted links for the inside frame coating stuff and seam sealers you might be interested in....
.
.
Hey BobB - Eastwood replaced the Correlless product with what they now call their' 'Rust Encapsulator' product, and boast it's a 'paint-over-rust' solution:
http://www.eastwood.com/rust-encapsulator.html
If you're curious about other products, I'm in the middle of doing the clone build now, and am documenting it:
https://classicoldsmobile.com/forums...-new-post.html
I posted links for the inside frame coating stuff and seam sealers you might be interested in....
.
Last edited by HWYSTR455; December 7th, 2010 at 04:59 PM.
December 7th, 2010, 03:33 PM
#21
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Hi Guys,
Ely442,
I have to admit that these last few years Rustoleum paint has gotten better. Not sure if they've figured a way to put some hardner in the paint or what.....but I have noticed it does last longer than before. That being said........and I in no way want to sound like a commercial for POR-15 or any other product....you'll find in the long term that POR-15 and Rustoleum are two entirely different animals. The main difference being that POR-15 seals with moisture, and once sealed is not porous. Rustoleum on the other hand is an enamel paint that cures thru solvent evaporation....meaning that as the solvent evaporates out of the paint to let it harden it leaves little tiny holes in the paint. These holes allow moisture to reach the steel underneath and eventually rust will form.
What I just recently did on a set of Rally wheels for my beater W30 was to sandblast the wheels, then paint them with gray POR-15. Before the POR-15 dried I sprayed the wheels with a gloss Smoke Gray Rustoleum for a topcoat. I know what some people are thinking......rattlecan paint on your wheels? I think the same way.......but I wasn't looking for a permanent solution....but am really impressed with how nice they came out. And I expect they will be durable as hell. A few years back I did the same thing on the wheels I have on a big industrial log chipper. They still look new today.
HWYSTR455,
Always makes me wonder when a company (nothing against Eastwood) stops carrying a proven product and replaces it with something else they claim is as good or better. Is it increased profit margin.....or is the product really better? Guess we just have to try it and find out. Or let someone else try it and find out.
) You also just reminded me of a question I've been meaning to ask about seam sealers, etc. Thanks.
Take care guys,
bob
Ely442,
I have to admit that these last few years Rustoleum paint has gotten better. Not sure if they've figured a way to put some hardner in the paint or what.....but I have noticed it does last longer than before. That being said........and I in no way want to sound like a commercial for POR-15 or any other product....you'll find in the long term that POR-15 and Rustoleum are two entirely different animals. The main difference being that POR-15 seals with moisture, and once sealed is not porous. Rustoleum on the other hand is an enamel paint that cures thru solvent evaporation....meaning that as the solvent evaporates out of the paint to let it harden it leaves little tiny holes in the paint. These holes allow moisture to reach the steel underneath and eventually rust will form.
What I just recently did on a set of Rally wheels for my beater W30 was to sandblast the wheels, then paint them with gray POR-15. Before the POR-15 dried I sprayed the wheels with a gloss Smoke Gray Rustoleum for a topcoat. I know what some people are thinking......rattlecan paint on your wheels? I think the same way.......but I wasn't looking for a permanent solution....but am really impressed with how nice they came out. And I expect they will be durable as hell. A few years back I did the same thing on the wheels I have on a big industrial log chipper. They still look new today.
HWYSTR455,
Always makes me wonder when a company (nothing against Eastwood) stops carrying a proven product and replaces it with something else they claim is as good or better. Is it increased profit margin.....or is the product really better? Guess we just have to try it and find out. Or let someone else try it and find out.
) You also just reminded me of a question I've been meaning to ask about seam sealers, etc. Thanks.Take care guys,
bob
December 7th, 2010, 06:22 PM
#23
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Hi HWYSTR455,
I asked the question of what exactly was eliminated from W30s to make them lighter from the factory...was it sound deadner, carpet underlayment, firewall insulation, seam sealer....etc? I posted it under the 442 section of this forum.
Noticed you mention Performance Years under your name. Great guys to deal with. Just dealt with Bob and Randy to have them make me up complete locksets for my 70 442 with the correct GM keys. Should be here tomorrow.
take care,
bob
I asked the question of what exactly was eliminated from W30s to make them lighter from the factory...was it sound deadner, carpet underlayment, firewall insulation, seam sealer....etc? I posted it under the 442 section of this forum.
Noticed you mention Performance Years under your name. Great guys to deal with. Just dealt with Bob and Randy to have them make me up complete locksets for my 70 442 with the correct GM keys. Should be here tomorrow.
take care,
bob
December 8th, 2010, 04:44 AM
#24
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Posts: 694
Ah, well, I didn't realize that they actually were lighter! But those all make sense, kind of like they did on the Road Runners and others.
Shoot, I probably added like 250 lbs on my project with all the underlay and all! Not that I mind, think I can make up for it with more power! Like many, I really just want it to last, get as much use and enjoyment out of it as possible.
Yeah, the PY guys are great to deal with, knowledgable, and very helpful! The forums over there have some pretty heavy hitters too, factory guys and all. And they have members from all over the world too!
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Shoot, I probably added like 250 lbs on my project with all the underlay and all! Not that I mind, think I can make up for it with more power! Like many, I really just want it to last, get as much use and enjoyment out of it as possible.
Yeah, the PY guys are great to deal with, knowledgable, and very helpful! The forums over there have some pretty heavy hitters too, factory guys and all. And they have members from all over the world too!
.
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