Drip Rail Questions

[Subzero]

I need to restore my drip rail caulk this week so I can better "waterproof" my truck. I still have about 60% of the caulk that hasn't come out from natural causes and age. I'm going to use POR15 to keep out the rust and fill it with DAP Gutter and Flashing caulk. Problem is I can't do it in one sitting and my truck is outside so it will get rained on. I will most likely take 5-7 days for everything to be closed back up after I take all the old caulk out. If I remove all the caulk inside the drip rail will this open up a seam and allow water to enter the cab and inside the roof? I'm really going my full 100% to get this truck ready for winter and can't thank everyone here enough for helping me out with questions.
Thanks
-Subzero

[Steel Clydesdale]

If I remove all the caulk inside the drip rail will this open up a seam and allow water to enter the cab and inside the roof?

Am thinking tarp and bungee cords--

Good luck.

Edit: Sorry, man--I was such a jerk. Just realized you're probably working on a Daily Driver....

[jimmy828]

When i replaced the drip rail sealant the only way i could see if water would get through is if there is any rot. I had very minor rust holes which i filled with JB Weld by forcing it into the small openings packing in as much as i could, let it dry, sanded it then went over it with tiger hair(bondo with small strands of fiberglass) So far it has been 2 years and has worked really well but i guess i'll find out in a few more years. I did use a sealant that was for the drip rail i purchased from the auto paint store and you can put it in a caulk gun. By using the proper sealant you can sand and paint it. If i can remember correctly, the sealant was around $11.00 Don't know how some product from Lowes would take an automotive paint.

[Subzero]

On the caulk it says will adhere to metal, paint too. It is paintable and another member recommended it in another thread here. I do not have much, if any rot but if I left the drip rail like it is I'm sure I'd have some sooner or later ( though I've learned that whatever rust you think you have, you probably have double). I can put tape over the rail to keep some water out if needed. I will go to the auto parts store and see if they have any "actual" drip rail filler but this caulk should work just fine I think even though its not factory quality. Looks like whatever was used before wasn't too good either IMO. If I do find anything I need to get it fast so I can get this bodywork done. Found the actual thread https://fordification.com/forum/viewtop ... ng#p649253 . Tell me what you think

Edit: Yes this is a daily driver but I also like it to be a show truck for the local town shows. Its more of a " if its nice out I drive it" kind of vehicle and isn't beat up on at all, when it rains its parked under a semi waterproof cover ( long story). I like to think of it as a DD with privileges

[Mancar1]

I always figured the drip rail was to keep water off u when you get in and out. Not to keep water out of the cab.

[Subzero]

that's what I thought its for, and to keep water from coming down the windshield. I don't know why there's even some filler in them in the first place really.

[jimmy828]

I guess snow would be a good example to have sealer. IT just sits there too long. After all the work i have done to get rid of rust, i'm doing anything to help prevent it in the future.

[Subzero]

all the work i have done to get rid of rust, i'm doing anything to help prevent it in the future.

I couldn't agree more with you. Where I'm at snow is rare but still, lately its rained everyday for the past week. Nothing has the chance to dry out before its soaked again.
I'm still open for more opinions with the caulk if everyone says it's probably a bad a idea then Im most likely wrong .

[motzingg]

i think the way cars and trucks were designed back in the day, the seals weren't so good so the drip rail keeps a sheet of water from pouring straight down the window where it will soak everything and run into the doors etc.

i ground mine out with a wire wheel on an angle grinder. a flat radial wire wheel got right in there and tore all the old sealer out of there.

then i liberally applied por15 to the bare metal, using a 'poking' motion with the brush to fill all the rust pits and put as much POR into all the small pinholes as possible.

then i used automotive seam sealer from 3m to liberally fill the seam, and wiped it smooth with my finger.


caulk has gotten really good over the years, and the new stuff is probably awesome, but my money is on 3M. plus i think they have an added rust inhibitor in the seam sealer that regular caulk wont have. plus it dries to just the right hardness so vibration wont crack it or cause it to separate.

If you have to do it over the course of several days, get in there and do the wire wheel, clean it out with TSP or your choice of paint prep cleaner, and the the POR-15 on it. Then it is safe to sit without causing further problems. Mine had a couple places where the pinch welds weren't real good and water could get in, but i'm not sure if thats how they came from the factory or if 50 years has opened up some seams.

the drip rail itself is spot welded on and i could see the seam where the two flat pieces come together around the door jamb being a serious cancer hot spot. On my truck that lap weld has had water in it and is blistered up in some places.

the POR will take overnight to dry, but the actual work of stripping, painting and sealing should only take 2-3 hours with the right equipment. the seam sealer works easily but be sure to have plenty of acetone soaked rags on hand for cleanup and a gloved finger handy to smooth out any lumpy caulk work. dip the gloved finger in acetone and it will work like a charm to smooth out the bead.

[Subzero]

Thanks for the help. I checked for drip rail cement at AutoZone and they didn't have anything like that available. I have some Prepand Ready POR15 paint prep pproduct to use. After doing some research and my failed attempt to buy some cement locally I've decided on using the Gutter and Flashing. I won't have the cash for anything else after I buy my bodywork things for some rust repair I'm doing on the doors. Besides, I'm sure this caulk is just as good or better than yesterdays drip rail filler along with putting POR15 down first. Its not anything like a normal everyday caulk- the stores don't even carry it by me. I don't have the right equipment needed to get into the rail unless I can use a Dremel tool. I know I'll be needing to fill in 2 rust spots just as the rail angles down by the door but hopefully that's all it will take and I already have glass filler waiting.

[Subzero]

On the POR15, should one good coat be enough inside the rail?

[motzingg]

por 15 says to always do 2 or 3 thin coats. i usually do one really heavy one to get in all the nooks and crannies, then do a thin one over that.

i don't know of a specific drip rail caulk, but i had to check around to find that advance was the only person around me with seam sealer in stock. it was 11 bucks for a 'caulk gun' sized tube (what is that like 10 oz or something) that should be enough to do my whole truck. any auto parts should be able to order it or amazon.com, eastwood, its pretty common stuff.

the big difference i think is the alkyd (solvent based) or latex (water based) chemistry. I have always felt that alkyd bonds to steel better because there is no water to put up a tiny layer of corrosion. I guess going over por15 thats not such a big deal, i'd just say for the work it takes to re-do it, 11 bucks is pretty cheap.

[Subzero]

Ok thanks, I'll check a few more places for the sealer. I wasn't sure about the POR15 and I didn't want to overdo it. Just one more quick question, How full do I fill the rail up? Do I fill it halfway up or to the brim?