Stepdown Rear Fenders; Painting and Seal to body Question

Unknown

Car is going back together slowly but surely. Finished fab/welding on the decklid weatherstrip lip where necessary, and ready to reinstall the rear fenders. Was wondering what other guys have used to seal the fender to the body. I was going to use 3M Strip Caulk, or some Seam Sealer. My other question is in regards to the actual gap between the fender and the body. When I go to shoot my last coats of primer and then the actual color coats, that gap is going to start to fill up. As a result, if I ever have to pull a fender off, the paint around it is going to chip. I guess that is just he nature of the beast....But anyway, can anyone share their experience and or tricks to dealing with that gap so I can duplicate as much as possible a factory look?

dave s

The caulking doesn't get painted! Wait until you have body and fenders painted before you install the fenders. Use 3M strip caulk about 1/4 " below top. As you tighten bolts, caulking will squeeze into place. Smooth and excess with ice ceram or pop-sicle stick. Remove any excess caulking with wax and grease remover.

Unknown

Thanks Dave. That answers the question. I have seen it done both ways (painted and not) and was not sure. The majority of the cars I have seen at shows and online have that gap painted over. Glad I asked.

rambos_ride

That 3m strip caulking does stay somewhat pliable - which is good for removal - but it can get pretty hard over time and if excess squeezes out and is flush with the top of the quarters I would think it would want to either crack from UV rays and/or gather dirt, weeds, whatever. I have always used strip caulking for inside - out-of-the- sun fixes for holes, leaky tailights etc..



The dolphinite seal mentioned in the Body and Fender book, and I believe was still the original material on my quarters noticed during teardown was still soft and pliable - almost like a putty material - even after 56 years. And it wasn't any farther up the seam than just above the sheet metal lip above the top bolt line with maybe just a very thin layer on the top - not filling the entire gap.



I don't know if this was the way they all came - just the way mine was during teardown. My car has been ultra original so far during teardown - no replacements or repairs.



I was going to look for a 3m product more close to the original dolphinite seal - something that doesn't harden - or I was thinking of looking into a thin waterproof foam tape that would compress and repel water from the joint.



What I'm wondering is where do you get the larger replacement foam pieces for the lower areas of the installation of the rear quarters and rocker panels?



So - Dennis, sorry this isn't a solution - per se - but thought I'd throw my .02 in!

hudsonguy

This doesn't expand on anything above regarding doing it the 'right' way, but it might relate to some stepdown owners.



My car was painted an Ivory color back in the late 80's at these fender seams. The work was done by a restoration shop, so I'm not sure what they used to fill these gaps before reassembly. Anyway, these long seams developed some kind of mildew over time, which really took away from what was still a very nice paint job. Not worth taking apart and doing over, but ugly nonetheless.



I used a good quality silicone bathroom caulk (white) that was readily available. Even though it's a different color than the Ivory fenders, it really covered up those ugly seams, and you barely notice it (the caulk).



Just a related topic that might help someone. They do make that stuff in several different colors nowadays, too.



Hudsonly,

Doug

rambos_ride

Silicone seal anywhere on the outside of a car is a body and fender mans nightmare!



The silicone will make paint work near impossible because of fish-eyes caused by the silicone.



good stuff - but use carefully

[Deleted User]

Dennis,



I am in the prosses of preping my car for paint, and I picked up a 3M product called 'Ultrapro Autobody Sealant' Part number 08301. It states on the tube that it is made for sealing interior and exterior body joints,can be painted after 40 minutes, won't shrink,and has good resistance to weathering after cure.

rambos_ride

I incorrectly stated in a prior post the Body Service Manual said to use "Dolphinite" seal - sorry - different section.



The quarter panels are supposed to be put on using

NOTE: Before installing rear fender apply a bead of Permagum No. 576 Sealer, starting from the base of rear foor hinge pillar and crossing quarter panel flange to frame at rear and to area 2 as shown in figure 108. Care must be taken to assure that the bead of sealer is unbroken and does not cross any fender attaching bolts.

That's direct from the horses mouth - so to speak! That would lead me to believe the correct type sealer is non-hardening and non-paintable.



From what I can find out about Permagum so far - is it is available in a cord type application similiar to 3m strip caulking and here are the specs. (Maybe 3m strip caulking will work if you don't allow it to extrude externally?)



CHARACTERISTICS:

• Seals out moisture, dust and dirt.

• Resistant to water, water vapor, temperature, alchohol, and

mild acids or caustics.

• Service temperature range from -30°F to 158°F (-34°C to

70°C).

• Excellent adhesion to wood, metal, plastics, glass, as well

as many other surfaces.

• Off-white color.

• Non-staining, non-drying



USES:

Any application which requires moisture, dust and dirt to be sealed

out and where ease of application is an important consideration.

the reliable source.....



SUGGESTED APPLICATION INSTRUCTIONS:

1. Adhering surfaces should be clean and dry.

2. Place Permagum over opening to be sealed and gently

press into place with thumbs.



SPECIFICATIONS:

Base Non-drying synthetic polymers.

Filler Inert materials (contains no asbestos).

Color Off White

Odor Non contaminating to sweet butter

Shrinkage Nil

Weight per Gallon Approximately 14 lbs.

High resistance to Water, water vapor, physical shock,

alchohol, mild acids and caustics.



Scott - Check that 3m 8601 - if it hardens up it will take an air chisel - or close to it - to get your quarters off again

[Deleted User]

When I read the original post, I took it that Dennis was asking about the gap between the fender and body AFTER the fender was mounted.The 3M product I memtioned is used to fill and even out that gap. That is why I sugested this paintable product. Rambo is right, do not use this for sealing the fender/body joint. When I removed my 1951 Comm fenders a few years ago, the sealer the factory used to seal the fender to the body was still soft and pliable.

rambos_ride

Oh yeah - back to Dennis in NY's original post!



The seam sealer Scott suggested indeed would work to seal the seam AFTER the quarters are installed and PRIOR to painting. If done correctly this would give you a filled gap that was more like the seams on a later model car. Although, using this method there would be no way to remove the quarter for any reason without having to paint and refinish the entire joint area again.



I think the only other "gotcha" I can think of with sealing the gap after the fact as described above would be on late model vehicles this seam sealer is almost exclusivley used in areas where there are welded/spot-welded seams. Being that the quarters on the stepdown bolt on there may be more flex at that joint than the sealer can take and split and crack.



Dennis - if the permagum type sealer was used as shown in one of my prior posts - I would just leave the top row of bolts loose enough to leave enough of a gap so that primer/paint doesn't fill it - or carefully wedge toothpicks or something small (maybe even small diameter clothesline) that can easily be replaced and removed during and after primer/painting as needed.



Then you would be able to carefully tighten the quarters down after painting. That will be the direction I take mine if I ever get it to that point!

Unknown

Dont want to throw a wrench into the works here, but according to an email I got from Ken Cates, the fenders were painted OFF the car and he has factory photos to prove it. This confirms that the seam sealer was never painted etc. I am going to prime off the car, but them back on and block them out, prime, block again and then do the color coats off the car. Yes, it seems like a lot of work, but I am picky about most everything, especially paint. Once I have them where I want them I will install with the 3M Strip caulk, which seems to be the way most guys have gone that I have received emails from. Thanks for all the feedback.