Waterproofing car...

[aarvig]

Not that I'm going to be driving in the rain, but our roads are occasionally damp with morning dew around here. I am concerned about the trunk, foot boxes and floor boards leaking water into the cabin. How do you go about waterproofing the cabin? Also, is there a product to put inside the wheel wells to protect from water spray and rock chips or is the aluminum fender liners that come with the kit up to the task?

[68GT500MAN]

I do not know about the "aluminum fender liners" that you speak of, but I applied two coats of brush on bed liner to the underside of the fenders. Has worked great for 10 years.
Doug

[DaleG]

Most should be waterproofed already if you applied silicon as directed when riveting the panels together. No?

[Jester]

I have found one area water can enter the cabin is along the vertical windshield mounting pillars where they pass through the body. I still need to seal the underside of each of the windshield trim plates with some sort of none silicone based putty.

[edwardb]

The areas you mention (trunk, footboxes, floor boards) will be 98% waterproof when assembled per the instructions. Adhesive, rivets, bulb seal, etc. If there are any gaps or openings (for example, around the seat belt tabs) use whatever method you like to fill those. Seam sealer, caulk, aluminum tape, whatever. You'll be good to go. Highly recommended to undercoat the body as already mentioned. Truck bedliner works perfect for this. Do it while the body is off and upside down. Extra coats in the wheel wells. I also put some on the wheel side of the fender liners. This isn't for waterproofing as much as to protect your body and paint. Plus it keeps down road noise and just plain looks better. There is a forum vendor (Alex's Custom Roadster Interiors) that sells full wheel well liners. I haven't used them but have seen them. Look pretty good. But there don't add any waterproofing really. Mainly just for appearance.

[DaleG]

Small, often overlooked areas like at the rear shock tower chassis brackets (trunk aluminum), and the passenger-side footbox exit tubing (unless you did the footbox entension mod) can be filled-in with silicone (I used left-over pieces of dynamat). Forgot about the windscreen post area, that too.

[aarvig]

The areas you mention (trunk, footboxes, floor boards) will be 98% waterproof when assembled per the instructions. Adhesive, rivets, bulb seal, etc. If there are any gaps or openings (for example, around the seat belt tabs) use whatever method you like to fill those. Seam sealer, caulk, aluminum tape, whatever. You'll be good to go. Highly recommended to undercoat the body as already mentioned. Truck bedliner works perfect for this. Do it while the body is off and upside down. Extra coats in the wheel wells. I also put some on the wheel side of the fender liners. This isn't for waterproofing as much as to protect your body and paint. Plus it keeps down road noise and just plain looks better. There is a forum vendor (Alex's Custom Roadster Interiors) that sells full wheel well liners. I haven't used them but have seen them. Look pretty good. But there don't add any waterproofing really. Mainly just for appearance.

Edward,
Are you saying to flip the entire fiberglass body upside down and use a roll/brush on bedliner on the entire underside of the fiberglass body...or just the areas above and around the wheels?

[edwardb]

Edward, Are you saying to flip the entire fiberglass body upside down and use a roll/brush on bedliner on the entire underside of the fiberglass body...or just the areas above and around the wheels?

Yep, the whole thing. And another several coats in the wheel wells. BTW, that's not just me saying that. Very common for these builds. I don't think it's mentioned in the instructions. Not until the body has been trimmed, cleaned, fitted, etc. Some guys have their painter do it. Others do it themselves. Like this:

http://i867.photobucket.com/albums/ab234/edwardb123/Factory%20Five%20Mark%203%20Roadster%20Build/Misc%20Pics/photo_3_reduced.jpg (http://s867.photobucket.com/user/edwardb123/media/Factory%20Five%20Mark%203%20Roadster%20Build/Misc%20Pics/photo_3_reduced.jpg.html)

[Gumball]

I didn't use silicone in my build, but instead used 3M clear seam sealer in tubes to seal between the aluminum panels. I also made flashing for areas where tubing passes through the panels or where the contact by adjacent panels was not to my liking (such as the inside wall of the driver's side footbox). I then used an assortment of brush-on seam sealant, butyl rubber (3M Strip Caulk and DynaMat), as well as aluminum tape to cover all other possible openings.

A good way to check for gaps is to leave the lights off in your shop and then put a drop light under the car or have someone hold it behind panels while you look from inside the trunk and interior for spots that need sealing.

I, too, used truck bed liner on the inside of my body, but not the whole thing - just the areas where the inner body is exposed to road debris and water. As an added measure of protection, I applied 3/8" neoprene pads to the top of each of the inner wheel wells.

Finally, for the last bit of protection, I a tonneau cover as well as a soft top & side curtains.

[PaulW]

Drove my Mark 4 in a 2 hour driving rainstorm. By the end of it I was soaked but that was inevitable. The major leak that occurred very quickly after the rain started was my left knee getting soaked from water dripping down the windshield pillar. I took off the window trim pieces and used black 3M sealer under it and it was good.

[Jeff Kleiner]

Not to discourage you in regards to waterproofing because all of the measures mentioned are just good build practice, but in my experience water intrusion isn't from what's kicked up from the road but instead by what falls from the sky. Everything you do to keep water from coming in will also keep it from getting out...unless you treat the car as a serious garage queen you will get caught in the rain...when you do you'll find that the lower floors of the footboxes can reach a depth of 2 inches pretty quickly...if you don't put a couple of small drain holes in now the first time you get rained on you'll wish you had...trust me on this (the second time I got caught in the rain the water was able to drain out ;)).

Jeff

[caropepe]

+1
...if you don't put a couple of small drain holes in now the first time you get rained on you'll wish you had

Here in the great Pacific Northwest being able to drain the water is most important - you're going to get wet.

Joe

[MPTech]

I agree with Jeff, got caught in a Monsoon coming home from LCS and the floor filled FAST!
One warning though, WATCH where you drill your drain holes!! You can hit a fuel line! (don't ask :eek:)

Also check in the front of the rear fender wells, in the area near the door post. My left side got soaked driving in very light rain. (I've got caught in several rains, but hey, that's what happens when you DRIVE it! I don't regret any of them.

[GWL]

I plan on putting a solid grommet in the bottom of the footboxes. All the British cars I've had have had them.

George

[aarvig]

I'm thinking of riveting in a fuel tank drain valve. The same type as is seen on aircraft fuel tanks. I wonder if that would work? You would have to depress it from the underside to get it to work, but it would be sealed otherwise.

[Jeff Kleiner]

I'm thinking of riveting in a fuel tank drain valve. The same type as is seen on aircraft fuel tanks. I wonder if that would work? You would have to depress it from the underside to get it to work, but it would be sealed otherwise.

No need to complicate it. When I got home after being rained on the first time I punched two holes in each side to let the water out by giving a big phillips screwdriver a couple of blows with a hammer! Went through carpet, insulation and the floorpan. Crude but effective; the holes are invisible from inside the car, water runs out from the top but doesn't get in from below.

Cheers,
Jeff

[PaulW]

When I got home from the 2 hour rainy drive I was very very glad that I had put a 3/4" drain holein each footbox. Just pulled the rubber plugs and it was gone.


Not to discourage you in regards to waterproofing because all of the measures mentioned are just good build practice, but in my experience water intrusion isn't from what's kicked up from the road but instead by what falls from the sky. Everything you do to keep water from coming in will also keep it from getting out...unless you treat the car as a serious garage queen you will get caught in the rain...when you do you'll find that the lower floors of the footboxes can reach a depth of 2 inches pretty quickly...if you don't put a couple of small drain holes in now the first time you get rained on you'll wish you had...trust me on this (the second time I got caught in the rain the water was able to drain out ;)).

Jeff

[Scud67]

I am just installing 2 small drain tubes through a grommet on the foot boxes (like an AC condenser drain hose).

[aarvig]

OK, I'll follow the KISS principle and put a couple of simple drains in the floor pans. Thanks for all the tips everyone!

[aarvig]

Yep, the whole thing. And another several coats in the wheel wells. BTW, that's not just me saying that. Very common for these builds. I don't think it's mentioned in the instructions. Not until the body has been trimmed, cleaned, fitted, etc. Some guys have their painter do it. Others do it themselves. Like this:

http://i867.photobucket.com/albums/ab234/edwardb123/Factory%20Five%20Mark%203%20Roadster%20Build/Misc%20Pics/photo_3_reduced.jpg (http://s867.photobucket.com/user/edwardb123/media/Factory%20Five%20Mark%203%20Roadster%20Build/Misc%20Pics/photo_3_reduced.jpg.html)


Edward,
I've been following your build. Thanks for going through the trouble of posting the process, it has been very helpful. I also appreciate all the advice you've given to me so far. Thanks!!

[smithbks]

not to hijack the thread, but why wait until the body is trimmed to put on the bedliner? I'm going to deliver my car for full trim, paint, etc. so I would need to coat it before giving it to the painter. And I have the gallons in the garage so I kinda want to do it :)

[edwardb]

not to hijack the thread, but why wait until the body is trimmed to put on the bedliner? I'm going to deliver my car for full trim, paint, etc. so I would need to coat it before giving it to the painter. And I have the gallons in the garage so I kinda want to do it :)

I said that, so I'll respond. First I guess it just reflects my personal build thought process going back to my days in woodworking and cabinet making, e.g. no finish steps until everything is cut, trimmed, fitted, etc. In reality there probably wouldn't be any reason the bedliner couldn't be applied before the body is trimmed and final fitted. Just wouldn't be my personal choice. One real point though. For both of my builds I did a rolled wheel well lip. This is intended to give a more finished look to the wheel well opening, and simulate the originals where aluminum was formed over a round metal hoop around the opening. The Mk4 is better than earlier Mk's, and the sharp edge of the fiberglass is less pronounced. So maybe not as much of an improvement as previously. But I still did this on my Mk4. Suble, but I like it. It means trimming the lip opening (like you would anyway), then adding a filet of HSRF behind the lip (inside the body) and sanding to give a rolled appearance to the opening. If done, that's a step that would need to be completed before the bedliner is applied. But again, reflects my personal opinion and build.

[Avalanche325]

As others have stated, the windshield pillars are where water got in when I was in the rain. Nothing happened, but the pillar on the drivers side is right above the fuse panel. Not exactly where you want water dripping in. I am going to do some kind of sealer when mine goes back together.

I like the idea of a non hardening putty. What about plumbers putty?

[NICK C]

Edward I have planned to roll the wheel well lips as you describe. Subtle but nice. What is HSRF? I may call it something else. Did you modify your body buck, or make a different one to flip the body on?

[edwardb]

Edward I have planned to roll the wheel well lips as you describe. Subtle but nice. What is HSRF? I may call it something else. Did you modify your body buck, or make a different one to flip the body on?

Sorry about that. HSRF = 3M Marine High Strength Repair Filler. Specifically made for vinyl ester glass. Good stuff. Part number 46012 is 1 pint. 46013 is 1 quart. Unless you have some other stuff to do, 1 pint should be enough. Available at most boat or marine places, like West Marine. I found the best price and quick availability was good old Amazon.

I didn't do any thing special. Just flipped the body over on its back. The pic I posted was at the painter for my Mk3. He had it on a couple saw horses.

[chrisarella]

I'm likely going to take a cue from what Jeep has been doing in the wrangler all these years and installing these in my floorpan:

http://www.carid.com/omix-ada/floor-drain-plug-kit-mpn-12029-21.html?gclid=CMuahsXhjMQCFcpZ7AodKHkAoQ

Cheap, simple, and effective.

[MPTech]

I'm likely going to take a cue from what Jeep has been doing in the wrangler all these years and installing these in my floorpan:


Are those plugs or drains? If they are plugs, I'd pass on them. In a rain storm, you don't want to have to reach down to drain the FBs! And they will fill up FAST in a downpour on the highway, while looking for an exit ramp! (ask me how I know!)

[chrisarella]

Are those plugs or drains? If they are plugs, I'd pass on them. In a rain storm, you don't want to have to reach down to drain the FBs! And they will fill up FAST in a downpour on the highway, while looking for an exit ramp! (ask me how I know!)
LOL sounds like a good time.

They're plugs made specifically to remove and drain water in several Jeep models. Perhaps the Jeeps don't have this issue because of higher ground clearance?

Where would I get drains that don't take in water?

[Jeff Kleiner]

Where would I get drains that don't take in water?

You don't need a 1" hole to let water drain; 1/4" will be fine. No plugs necessary or worries about taking anything in from below because the footbox floors are only 6" off the ground and well out of tire spray range. Everything coming in will be from above unless you drive into water deeper than the floor!

Jeff

[chrisarella]

You're correct that an unplugged 1/4" size hole might be plenty for most. I should point out that I live in FL where rain is measured in inches/hour and forging water on the road is a regular occurrence. Even if I seal up the windshield pillars the volume of water coming into the car could be quite excessive from above and below, so I'd want that hole sealed.

Perhaps a petcock drain on the driver and passenger sides would be good:
http://www.amazon.com/Porter-Compressor-Replacement-A17038-N286039-2pk/dp/B00J5S9A04/ref=sr_1_19?ie=UTF8&qid=1425481524&sr=8-19

I also remember seeing a push-button drain valve available out there somewhere but can't find it. Anyone know where I could get one of those?

[rich grsc]

Those would take a long time to drain out (1/8" hole), and hang down on the bottom of foot box.. Way over thinking a simple solution.. 1/4" hole.
Oh, a push button drain,, you going to hold it open for a 1/2hr?

[Jeff Kleiner]

OR...

https://www.google.com/shopping/product/7609398880288360915?q=bilge+pump&rlz=1C1SKPL_enUS463US515&espv=2&biw=1024&bih=653&bav=on.2,or.r_cp.&bvm=bv.87519884,d.eXY&ion=1&tch=1&ech=1&psi=rUb3VM31K4erNr_TgKAL.1425491877838.5&prds=paur:ClkAsKraX7bTdq4Yk1BI3bBusPmpmgMwzmaIkeQ1 zoK5UK17f5Z_wtKYsYnZpan0VtO-SBsIQ5plOUmHoVxaCL0gYNLHVZ_AT80YSk4pDDUYRfLSbaEkgW oCWxIZAFPVH728Ivx-fDciJ05ZU5sIMsw_bdngrQ&ei=wUb3VP3ANMKmNoWlg8gD&ved=0CP4CEKYrMA8


;)

Jeff

[DaleG]

OR...

https://www.google.com/shopping/product/7609398880288360915?q=bilge+pump&rlz=1C1SKPL_enUS463US515&espv=2&biw=1024&bih=653&bav=on.2,or.r_cp.&bvm=bv.87519884,d.eXY&ion=1&tch=1&ech=1&psi=rUb3VM31K4erNr_TgKAL.1425491877838.5&prds=paur:ClkAsKraX7bTdq4Yk1BI3bBusPmpmgMwzmaIkeQ1 zoK5UK17f5Z_wtKYsYnZpan0VtO-SBsIQ5plOUmHoVxaCL0gYNLHVZ_AT80YSk4pDDUYRfLSbaEkgW oCWxIZAFPVH728Ivx-fDciJ05ZU5sIMsw_bdngrQ&ei=wUb3VP3ANMKmNoWlg8gD&ved=0CP4CEKYrMA8


;)

Jeff

Man, I hope I never need one of those!

[MPTech]

Petcock?? Are you going to get under your car in a pouring rain to open it?

Forging water? We did this on our Arkansas cruise in October and not one guy complained about wet feet!

https://www.youtube.com/watch?v=G4SE-1I8Uao


Keep it simple, 1/4" holes. That's all you need (you'll never see them and will not get water coming up into them. You can even put 2 of them in each footbox floor if you like. :cool:

(although I like Jeff's suggestion of a Bilge Pump too!! :eek:)

[Jester]

Now that's one of the coolest videos I have seen! A great bunch of snakes crossing a river.

Thanks for posting!


Petcock?? Are you going to get under your car in a pouring rain to open it?

Forging water? We did this on our Arkansas cruise in October and not one guy complained about wet feet!

https://www.youtube.com/watch?v=G4SE-1I8Uao


Keep it simple, 1/4" holes. That's all you need (you'll never see them and will not get water coming up into them. You can even put 2 of them in each footbox floor if you like. :cool:

(although I like Jeff's suggestion of a Bilge Pump too!! :eek:)