hack job - what about roofing cement for undercoating / seam sealer?

[milner351]

well - the DD required some welding to patch up the spring perch to the inner fender / subframe on one side, and on the other side - a rust hole of not so much structural importance - but a hole none the less.

as I'm not real interested in the looks of this thing and didn't want to spend the time to grind down everything to make it look smooth....

I looked at the $11 gallon can of roof cement and thought to myself - "that might just work perfect"

we'll see how it holds up.

anyone else ever try this?

[Not A Duster]

Re: hack job - what about roofing cement for undercoating / seam sealer?

anyone else ever try this?

Nope.

But I'm interested in seeing your results.

[Caddyman]

Re: hack job - what about roofing cement for undercoating / seam sealer?

Yep, when I was a kid.

It doesn't ever fully dry, and makes a huge mess when trying to remove it later.

If you want super cheap, think about using some cheap, non-silicone caulking compound that smears on seams like sealer...and it even looks the same.....

disclaimer: my dad owned a large roofing company for 40yrs...he could fix anything with roofing cement...me? not so lucky with it....

And don't undercoat anything. Its just a way to trap moisture behind the coating. Its better to use cheap rattle can paint, and coat every few years as needed.
Down here, most of the "rusty" cars we have?
Were all undercoated.....

[milner351]

Re: hack job - what about roofing cement for undercoating / seam sealer?

good points.

My buddy kept his '86 Ranger alive a long time by crawling under it every fall with a few cans of cheap black paint.
another friend kept his fox mustang rust free for years by spraying it with used oil every fall - sure made a mess of his street parking spot tho! :o

Ironically - the rust I just repaired on this heap (a '95 mercedes) was under the seam sealer and undercoating >

(which is used in copious amounts on these things - the seam sealer was over 1/4" thick in several spots, and undercoating is consistantly 1/8")

[SuperBuickGuy]

Re: hack job - what about roofing cement for undercoating / seam sealer?

problem with roofing tar is the metal continues to rust.... it's a true temp fix - as eventually the entire metal under the patch will rust away; then the roofing tar will fall out..... use POR 15 and fiberglass for a permanent fix

[milner351]

Re: hack job - what about roofing cement for undercoating / seam sealer?

well, I did paint it before I tarred it....

again - this is hack job DD stuff..... not worth breaking the seal on the POR can.
;)

[SuperBuickGuy]

Re: hack job - what about roofing cement for undercoating / seam sealer?

I've had a can of POR 15 and fiberglass mat for at least 10 years and use that exact excuse every time I think about opening it for some job. Eventually it will become a cab corner on my Studebaker..... wonder what the shelf life is of that stuff?

[Not A Duster]

Re: hack job - what about roofing cement for undercoating / seam sealer?

And don't undercoat anything. Its just a way to trap moisture behind the coating. Its better to use cheap rattle can paint, and coat every few years as needed.
Down here, most of the "rusty" cars we have?
Were all undercoated.....

You have to put some undercoating in the wheelwells and inner fenders. if you don't the sound of stones and road debris hammering on 'em will make you nuts as you drive.

[milner351]

Re: hack job - what about roofing cement for undercoating / seam sealer?

I'll be interested to see how this stuff holds up - I wish I could find something similar but that actually cured over time - this stuff has been on a few days and is still soft.... oh well, it's a DD.

I'll be interested to see how the bedliner material we put on the floors of Seths' 'bu holds up too, I can think of lots of uses for that stuff if it holds up.

[VTJUNK]

Re: hack job - what about roofing cement for undercoating / seam sealer?

When we did the frame repair on the '95 F150, we welded the hole, ground it down smooth, then just put axle grease on it. After a couple of weeks the dirt that gathered made it look like the rest of the frame.

The only way to keep rust away is to spray with oil, or coat stuff with grease and a brush. WD-40 sparyed on chrome bits just before winter works great too. I had a customer that would brush a coat of vaseline on his bumpers to keep them nice. In the spring he would just wash it off.

I would put some grease over the area you repaired. In a few weeks you won't even see it.

[Caddyman]

Re: hack job - what about roofing cement for undercoating / seam sealer?

When we did the frame repair on the '95 F150, we welded the hole, ground it down smooth, then just put axle grease on it. After a couple of weeks the dirt that gathered made it look like the rest of the frame.

The only way to keep rust away is to spray with oil, or coat stuff with grease and a brush. WD-40 sparyed on chrome bits just before winter works great too. I had a customer that would brush a coat of vaseline on his bumpers to keep them nice. In the spring he would just wash it off.

I would put some grease over the area you repaired. In a few weeks you won't even see it.

This reminds me of a friend here that owns an older, painted, non-galvanized boat trailer (even our fresh water is brackish/salt in places).

Gary would carry a 5-gal bucket of used trans fluid/oil/gunk with him EVERY time he launched his boat. He'd leave the gooey bucket in the shop truck all the time.
He would "mop" the goo all over the trailer/springs/hardware before and after the boat went in the water, using an old cut-off dollar store mop.

Surprisingly, in 10+yrs of use, every summer, his PAINTED trailer looks better than most ALUMINUM trailers (at least the steel hardware stuff).

It sounds stupid, but it works great.

[milner351]

Re: hack job - what about roofing cement for undercoating / seam sealer?

I'm betting Gary's grass doesn't grow well where he parks that trailer!

I'd love to see the look on an environmental officer's face at the boat ramp watching that routine happen!

We had a guy inspecting folks launching early in the spring to make sure there was no green antifreeze getting into the lake....

[DanStokes]

Re: hack job - what about roofing cement for undercoating / seam sealer?

Keith has the best cure - Samsonite!

Dan

[Caddyman]

Re: hack job - what about roofing cement for undercoating / seam sealer?

I'm betting Gary's grass doesn't grow well where he parks that trailer!

I'd love to see the look on an environmental officer's face at the boat ramp watching that routine happen!

We had a guy inspecting folks launching early in the spring to make sure there was no green antifreeze getting into the lake....

When the floating oil slick would start to "shimmer" he would tell anyone that asked "I must have a little fuel leak thats being picked up by the bilge pump!!!!....Ya'll better back up, just in case it catches fire or something!!!!"

Nobody would stay around to quiz him afterwards......

[DanStokes]

Re: hack job - what about roofing cement for undercoating / seam sealer?

John -
I'd rather see you use self-etching primer and a spray can of some kind of paint. Seam sealer is good, too. There's a reason auto paint products are made the way they are.

Dan