Sealant / adhesive recommendations

[mungus]

Hi,

I've had bad luck with the OEM wavy type spray on sound deadener, reacting with the commonly used (and well cured) Sikaflex panel sealants / adhesives. Like their popular 227 type. The result is a permanently sticky surface where the 2 meet, (it never ever dries...).
I emailed both Sikaflex and Motospray (sound deadener mfg) but they offered no solution. Denial or bad luck was the theme...

This has caused me issues in the wheel houses where I sprayed the sound deadener over the sealed centre seam.
After well over a year of waiting for it to set, to no avail, I've decided to scrape the sticky sound deadener off and start again.

Obviously the OEM seam sealer didn't have this reaction to the standard wavy sound deadener used by Ford in the day. But just what product do folks buy these days to seal panel joins in places where sound deadener is applied?

Appreciate your recommendations...

[hybrid]

I'm not sure what normally sets it, but have you tried giving it a nudge with some heat from a hair drier or heat gun?
I've still got a bottle of some stuff here that Ozbilt gave me years ago and still haven't used, but I'm guessing it's probably one of the ones you have already tried. It needs a special gun that I don't have which is why I didn't use it right away.

[mungus]

Yes it sounds like the sound deadener I used. Its the traditional Butyl type stuff. In OZ its offered by Motospray.
To get the OEM wavy effect you have to use a special nozzle / gun. Which instead of a paint type nozzle has a longish tube with quite a big ID.
They're cheap to buy. I think in the states they call them a "Schutz" gun.

Tried heat to make it go off, but alas it does nothing but make the sound deadener softer while its warm. Seems more like the stickiness is due to some chemical interaction between the Sikaflex 227 and the butyl deadener. I have some Sikaflex 527 AT now, but as far as I know the only difference with that is the shelf life?

Anyway not worried about the sound deadener, as that's what I'm going to use as its the OEM type product and it looks right.
Its seam sealer recommendations I'm after. Plainly other restorers are using something that doesn't have this reaction. So I just want to know what they use... The creamy white OEM stuff they used in the factory didn't have this issue. (albeit it had some other probs).

[hybrid]

This is the stuff I was thinking about. It's probably not what you need.
I'm supposed to be spraying this under the front guards to prevent dents from stones coming off the tyres.

https://eshop.wurth.com.au/Product-cate ... n4QAvD_BwE



For seam sealer on mine, I just used some stuff from supercheap and it was fine, but I wasn't putting it over epoxy.

[mungus]

Thanks for the reply.

Wurth has a good name so I guess it would work fine. Not sure it matches the wavy appearance of the Butyl OEM stuff, which is what I'm aiming for. Interesting they label it "Korrosionsshutz" in German, as Shutz is what Ford / GM called the gunk they applied in the 1960's... So I guess that's where the shortened term originates.

The reaction with the seam sealer that's the problem. I'm thinking the OEM caulk wouldn't have been polyurethane, like the modern Sikaflex ones are. (227/527AT). Maybe its the hydrocarbon solvent in the butyl stuff buggering the surface of the 227? There are a couple of rubber based sealers that I'm looking at now.

Your suggestion might well be another way around it; that is I'll keep using Sikaflex sealer / adhesive, but with the Wirth product over the top using my Shutz gun, instead of the Motospray butyl product. I'll check the Wurth TDS and see what its made of. The Motospray stuff is basically bitumen with a petrochem solvent.

Any suggestions appreciated.

UPDATE: That Wurth can you attached isn't their underseal / deadener as such. Wurth make an actual "underseal" for wheel houses etc. And guess what, its Bitumen based too! Just like Motospray's. They call it underbody shutz.

https://eshop.wurth.com.au/Product-cate ... etailpageA

So I guess that's still the industry standard! So back to looking for another caulk / sealant. Who knows, maybe the OEM style sealer is still available?

[ozbilt]

The Wurth stuff I gave hybrid is the sound deadener that also serves as as a guard against stone impacts. It was what I used on all my builds in the USA and Australia as it gave a close texture and finish as what Ford used. The Wurth product is also water based. Goes in a special gun but can be emptied into a "shultz" gun.

You will not get anything that is closer to the OEM compatible as the original product contained asbestos.

[mungus]

Thanks Kerry, have a shutz gun so might buy a can and give it a go.
Water based shouldn't react with anything silicon I'm guessing...

UPDATE: That Wurth Aqua Shutz worked a treat! Looks factory correct, dried fast and no stickiness. I guess if I was being really picky its not as jet black as the old bitumen stuff, more like a darkish charcoal. But I doubt anyone would notice... Thanks for the idea Kerry.