Hey so I have a 66 coupe v8 mustang....regular old mustang....im gonna do a restomod to it and its at its beginning stages...was wondering what would be the best way to attack pinholes in this roof....ive heard of using epoxy then a thin coat of bondo ontop? Does that sound like it would work?



Here are the worst holes

 

That needs to be cut out and replaced with some good metal. Please don't use epoxy. If done correctly you will only need a small amount of bondo or filler

 

oh sorry forgot to add the Welcome to TMS and please post some more pictures of your car.

 

So from a structural stand point....if I filled it wity duraglass would it be okay? Or do I need a whole roof skin

 

That would be the cheap( and in if you intend on keeping it) wrong way to go, I have the same on my 69 grande because of the **** vinyl roof, it won't be that expensive to have a shop do it, if your gonna do a restomod and spend money on it why leave a lose end like that, but that's just how I see it

 

I just sold my coupe roof I had spare too......damm

 

Do u think It would crack later if I did duraglass it?

 

It'll just keep rusting if you don't cut it out.

 

I was planning on using POR-15

 

Hmmm idk if I was you i would just cut a little square out around the rust and just make some patch panels that way you don't have to re skin the while roof but still get the rust taken care of

 

Im kinda scared of cutting squares in my roof....with my luck ill screw it up...

 

Just make a template out of tape

 

Yeah but getting the contour right might be difficult

 

I'm with him. Something like por15 or rust encapsulator is good for surface rust or prevention, but if you've already got pinholes, you're going to want to cut it out and start with fresh metal. It's pretty intimidating - I know, I'll have to do my roof at some point. I'd ask around for someone with a welder and experience, or a competent shop.

 

You can purchase new roof metal with the contours already there too

 

I would take it somewhere and have it done, then. It's not too difficult to put new metal in there for a person with the right skills and experience.

IMO that is the right way to do it, I would hate to have any bondo (or similar products) on a resto I was doing.

 

yep and you have to be careful about putting to much heat/weld at one time, that will cause warping

 

sounds to me like maybe no access to welder, trying to stop the rot- at least for a while... far best to cut it out, but if you ARE going to try jus to fill it, I have a suggestion...

one spot in the floor of our 65 galaxie(lots of rust repair pics here: http://www.flickr.com/photos/8323217...7634932178345/ ) had pinholes, right over a spot with a lot of structures under it- cutting it out woulda been easy, but after welding, access to paint/seal woulda been about impossible...eastwood has the neat little internal frame coating nozzles, but I wasnt to sure about the tight area, not being able to see inside, etc... sorry for long story- anyways, i decided to cut out around the thing(only about a quarter size- looking thru with a mirror, rest was perfect, just very light surface rust on bare metal. sprayed por15 inside, soaked a small piece of glass matting with POR instead of resin, pushed it thru the hole, held it up with a little bit of wire, let it cure, next day, put a layer of thin glass matting soaked with POR on top of that- tell you what, that stuff is rock hard, dont think it will ever come up.

ANYTIME you have bare metal (even mint/clean) or surface rust, do yourself a favor and treat it with 'Ospho' or whatever brand of phosphoric acid metalprep your local paint/hardware store carries- even new steel will have microscopic rust starting unless its in a zero percent humidity environment, and while self etching primers do a pretty good job, they cant hold a candle to a mild acid etch to convert any iron oxide into inert iron phosphate before painting...the etch also gives paint incredible bite...if you etch lightly rusted metal then POR over that, youll need a grinder to remove it.

on POR, I learned the hard way about opening the can=ruining the can overnight if you live in a humid area...I get cheep hardware store clear tubing, take a 6" loop of about 5/16 od, take a similar sized phillips screwdriver and pound 2 holes in the lid...push the tubing in, very very little air(humidity cures it) gets in, ive had cans last several years this way...just pull the tube out on one end, pour a little in a disposable tray, push the tube back in. stupid sounding, but it works well...after a few times, the paint/tube will get hard to pull out, but its stretch enough, it will pop out- just watch it dont flick paint on you...thats the messiest stuff on earth, and God forbid if a drop would get in your eyes...

seriously- try some POR, even on a piece of saturated papertowel or something to cover a hole in a scrap piece, it sets up harder than glass resin, and its composition prevents rust... I will never buy polyester resin again.

all that said though, cutting/welding is way to go...its really not hard to cut the rust out- I prefer thin cutoff discs in a 4 1/2" grinder, go slow to keep heat down, you can cut with zero distortion... yes on a roof, or any relatively flat panel warpage when welding can easily happen, just gotta keep the heat down- tiny spots, let cool... the contour can be beat into a flat piece easily, should need very little filler to skimcoat/block down...

just remember Ospho after welding/before paint

good luck on it-
Tim

 

Dang dude alot of info...yeah i mean there is no better alternative besides metal but I doubt duraglass would ever crack anytime that I would own the car...and duraglass dont rust....thats my theory.. but then again...im no restoration expert....I do have a welder and plasma cutter....so the tools arent an issue....im just no expert on using the tools

 

I do have a guy I know that does rust repair on classics...ill ask him for input on cutting small squares out....im trying to keep bondo off the car...but if I have to use a thin coat ill have to suck it up and deal with it