Seam Sealer vs Body Filler

[Rally Pack 2000]

Tidying and painting around the engine bay, most of the seam sealer has long since fallen out or gone so hard I had to chisel bits of it out. Bought some Sikaflex Auto sealer which listed as seam sealant and it just seems the same as any silicon sealant to me. When it dries its just has a flexible rubbery feel to it. This sealant is supposed to go around the lip in front of the plenum chamber and up to the bonnet hinges. But this is the area that is really prone to rust and its this area where water would get trapped under the sealant and rust even faster. They say you can sand it and paint over it but its just like flexible silicon once dried, you couldnt really sand it like a filler and if you paint over it and pressed it wit your fingers wouldnt the paint just split? I dont remember the original stuff being this soft back when the car was relatively new but then again I didnt go pressing into it to see if it was soft or not. Anyways do most of you just replace the rubbery seam sealer with the same or do you mould some metal filler into there instead? Or is there some kind of seam sealer thats harder and sandable but flexible enough not to crack in these positions?

 

[PeterMEscort]

Try Sikaflex 432 White. Hard enough to sand and can paint.

Probably the closest to OEM.

[Craig89]

The stuff you used sounds about right as to regards of what you get when asking for seam sealer. I have used Tiger Seal and another very simular no name brand and they are both as you describe. They are supposed to be flexible so the paint doesnt crack when the body flexes at that joint. It does paint over just fine but I have to admit I dont go prodding at it afterwards

 

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[Snapper]

Sikaflex and Tiger seal are a polyurethane adhesive with good flexibility and very strong adhesion however they are not fuel and oil resistant

[JP.]

You might consider brushable seam sealant.

[Rally Pack 2000]

Try Sikaflex 432 White. Hard enough to sand and can paint.

Probably the closest to OEM.

 

The one I purchased was a Sikaflex 227 in white. Thats what their website recommended for car seam applications but it just seems too spongy to me so I will investigate 432 you suggest.

[Rally Pack 2000]

You might consider brushable seam sealant.

 

I think the grooves are a bit deep for a brush on one as it really needs to fill some gaps in places.

[classicwhitey]

I think the grooves are a bit deep for a brush on one as it really needs to fill some gaps in places.

glove up and run your finger along it pushing the sealer into the gaps

[PeterMEscort]

"Thats what their website recommended for car seam applications but it just seems too spongy to me so I will investigate 432 you suggest."

 

Websites are crap.

 

Always ask someone (such as a professional) who is doing the work on a daily basis, who knows what is good, and what the latest trends are, and exactly why they are doing it that way......unless you like all the pain and suffering and continual trauma of making continual mistakes and reworking while you are learning.

[Rally Pack 2000]

Got up early this morning as its due to be above 40 degrees C later in the day so I wanted to put this seam sealer on while the temp was nice but what I thought was going to be a simple apply and wipe job proved to be a tacky nightmare. I really made a mess of it! I certainly hope this stuff is sandable like they claim because I have alot of smoothing out to do! You have to admire these people with skill that can get this done in a minute or two and the job is as neat as a pin. If I had to do the job again I would do it in two stages. One to fill in the gaps and then let that dry then apply another think layer just to smooth everything out.