Spray undercoating

Ok, getting ready to undercoat one.
I'm using the 3m brand with a Schultz gun. Sprayed it at about 40 psi. My issue is its a stringy mess. It looks like cobwebs in the inner fender ,,,not happy.

Any recommendations of either a different product you've used or am I doing something wrong. I think I used this same stuff back when I did my challenger and I dont remember having this problem then . I'm not against using the can stuff either if its thick.


This isn't a concourse resto, but Im trying to look something like OE if I can

Use resto ricks undercoating... I find it takes mulitple coats to look like factory, but sprays nice.

I've used both Resto Rick's stuff and 3M - never saw stringing. I wonder if your product separated.

I'd use Ricks if going original. I've used the 3m stuff and didn't like. My last car I sprayed Bedliner because it's going to be a driver and I love it.

This car is very much going to get driven, a lot and hard.
Mind if I ask what brand bed liner materiel you used? Is it shiny or pretty dull looking ? A buddy of mine who does painting advise this very idea, and right now I'm leaning that way pretty hard

I want it protected and if I can get reasonably close to the texture it has when new ,,, The cars owner and I'm good with that.

I asked someone else who had use the Resto Rick stuff and sounds like he had a similar experience that I did , especially the mess part.

Try dropping the air pressure down.

I just did a job with Resto Ricks stuff and I thought it sprayed out nice. I used a plastic can that did not like Ricks stuff so I'll have to find another gun setup. It dries hard and will not rubb off. I did a job with the 3 m stuff years ago and it did not ever get hard enough for my taste.

I'd say it's like a semi-gloss? I used Herculiner and sprayed it with an undercoating gun I'm thinking around 50 psi. You'll have to play with the psi to see what works good for you and it takes 2 good coats to cover but don't spray to thick or it will run just like anything else. Just make sure to stir it good. This Herculiner has an aggressive texture also it but I like it. Now if your looking for something with a little smoother texture and you can also add paint to it and change colors it is called Hippoliner. I sprayed my truck bed with it and this stuff is also pretty dang sweet and it's harder than a whores heart. I don't have good enough service to download the pics tonight of it.

Bill, I used 3M for some touch ups and was happy. I think I used 30-35 psi and was at 12 inchs away
I always go with Resto Ricks when needed
Good Look.
Bob

Bed liner is fine if your going to keep the car... go to sell it and it looks like its covering up stuff a lot more than undercoating. I've done it before... if the prep isn't really good, be prepared for it to fall off in chunks/crack etc. Undercoat sticks a lot better and flexes better.

x2 on trying to vary the pressure.


I used UPOL Raptorliner Bedliner, very good stuff to work with and lays down very nice. Rock hard surface.

I use Wurth Undercoating some, sprays great and closest to original out of a spray can. Resto Ricks stuff if shooting from a gun.

That looks good.

[quote=Silver70]I've done it a lot! There is so much wrong with this post right here it ain't funny. I scraped the factory undercoating off of my car and torched some of it off. Believe me if anything is going to hide anything it's factory undercoating and Bedliner sticks as good and will not crack and it does flex. Bedliner will show more than undercoating and you just can't gob it on and cover up $hit like your letting on.

You must be using spray can bedliner if you think it's thinner than undercoat per coat. Good bedliner is like 3 times as thick if not more per coat. Like I said, you want to hide stuff, use bedliner. I've used both at least 20 times and good resto rick undercoating looks so much better. I used to think the same as you, but not after the last car, never again... it's good for a truck bed and that's it. Bedliner looks like plastic, just looks out of place on a muscle car.

Has anyone tried baseing with bedliner and top coating with Resto Ricks undercoat?

To the original poster... If you're getting cob webs, then the solvent in the paint isn't all that compatible with the paint itself and/or is evaporating too quickly. Many companies have swapped out "good" solvent and replaced it with acetone (not a very good paint solvent & evaporates fast, but gets around various states' "VOC" regulations).

You can put the gun closer (less time for solvent to evaporate), turn air pressure down as others have suggested, or maybe thin the paint with a slower solvent ("summer blend" if you have that option).

Bedliners are usually either polyurethane or polyuria. Polyurethane dries slower & is more flexible. Polyurea dries in 15 seconds and is more brittle. There are also some polyurethane/polyuria hybrids out there.

Thanks for the comments.

I'm going over this week to talk to my local paint rep and see what he suggests . Maybe I just got a bad jug of material. I think Ive used this same stuff before with excellent results. So we'll see .

I wonder how some of this stuff would act if a car fire were to happen?

Before I installed my NOS quarters years I go I sprayed some 3M inside my quarters just to save time from having to do it after I installed them. I had the same result as you. I ended up scraping everybody bit of it off.

Your wrong there. The factory undercoating was put on thick, real thick. Not 1 car will look the same because they didn't care back then. As long as the car got covered they didn't care what it looked like. Like I've said I've scraped off a bunch of factory J55 cars and the results are not consistent. The stuff today is still not like the Undercoating they had back then. Try to duplicate this first pic of factory undercoating. I don't know what kind of junk bedliner you were using but it's obviously not the same what I use and doesn't look like plastic lmao. I've got some old pics somewhere if I can get them to download I'll post them. I done the 2nd pic about 4 years ago and in person everybody loved it and they even loved the Hippo liner I sprayed last year even better but I can't get those pics to download. Like I said If your driving the car use Bedliner unless you want to use undercoating and you like the dirt look that sticks to it but your restoring one correct and is a trailer queen I'd use the undercoating.

Even if you drive a car, good epoxy and factory style primer looking paint hold will up perfectly fine unless you think your driving the general lee and driving through gravel and off roading. New cars aren't even undercoated... my 230k mile 2001 truck still has primer on the underide and it's driven year round, mud/gravel, snow/salt etc.

There's no need for either other than the wheel wells and inner quarters unless you want to cover up flaws.

And I repeat, use bedliner on a car and see how people react when you go to sell it... if it's a valuable car, good luck! There's no need for it and no place for it on a muscle car.

I like Ricks stuff and have used the 3m stuff as well, both with no issues. I do use a 3m gun and keep it meticulously clean as undercoating sets up fast. As noted, air pressure and volume play a big role.

This right here is just frigging hilarious. I've worked from Washington, PA to Philly and all over Ohio the past 20 years. I know what gravel Roads which is Limestone and Salt and Calcium Choride does to your car. I've watched 2 Dodge trucks a Ford and Chevy just Rot away. I've used Undercoating on all my hunting rigs in the past and I love the dirty gray look it leaves when you try and clean it up lol. If I had a trailer queen or live in Miami Beach or Southern Cal I wouldn't use either but I drive my cars. So after reading your hilarious comment I'm done with this post.

You seem to think you know more than you actually do... all the rams you see rust out in the wheel wells for example is because they trapped dirt/junk between the wheel house and bed side. Nothing undercoat or bedliner will change... goes the same for gm and fords. No under coat or bedliner is going to be able to get into this area. In fact it would just help trap it more than just pressure washing it now and then. Your not bedlining inside the frame, body mount areas etc. If you want to avoid rust out, your better off spraying oil on them.

230k and northeast 4x4 driven winter/gravel etc and yet my trucks not rusted out underneath... explain that keyboard pro! Go lay some more pipe, you obviously have no idea what your talking about.