Log In | Register
Skip to main content
Topic: Finding leaks or look at all the bubbles (Read 93 times) previous topic - next topic
0 Members and 1 Guest are viewing this topic.
Finding leaks or look at all the bubbles
Yahoo Message Number: 119534
In an attempt to pinpoint a hard to find leak in an mature LD, I recently used about 300' of 2" wide masking tape to seal all the exterior openings including the doors, windows, stove fan vent, escape hatch and all the exterior storage compartments.
The interior was pressurized by using the dash A/C blower and the two interior ceiling fans, set to high intake(blowing into the interior).
A very strong soapy water solution was brushed over the exterior walls and roof.
Bubbles appeared in dozens of places along the horizontal and vertical seams and end caps.
Unexpected large leaks were detected in the tail lights and roof A/C. It was shocking to see how many potential leaks there were, especially in the sheet metal seams. I had always thought they were well sealed at the Factory. Another wrong assumption.
The well fitting coach door leaked very badly.
A fellow Lazy Dazer once told me that he never bother to open a vent or window when using their cat heater because the coach leaked so badly. While I do not use and would not recommend this practice, he is probably right.
After seeing so many bubbles in the rear end caps, I now know why the rear columns in older MBs and T/Ks are subject to rotting.
If these seams have opened up on your LD, do not assume that they are still water tight.
It is a lot of work to reseal and well worth the effort to help preserve the wooden frame.
http://www.flickr.com/photos/lwade/sets/72157625671994909/> Now, I need to figure out how to seal coach doors better. Even the best fitting doors are a major source of air infiltration.
2001 MB
* Not to be confused with Larry W (3000 of my posts are actually from expert Larry W due to Yahoo transition mis-step)
Re: Finding leaks or look at all the bubbles
Reply #1 –
Yahoo Message Number: 119536
Quote

 In an attempt to pinpoint a hard to find leak in an mature LD, I recently used about 300' of 2" wide masking tape to seal all the exterior openings including the doors, windows, stove fan vent, escape hatch and all the exterior storage compartments.
Larry,

Good job!
 This is an applicsation that is well suited for (don't laugh) "Capain Tolley's Creeping Crack Seal" (CTCCS)!!
 http://www.epoxyproducts.com/capt.html

CTCCS is a water thin whitish liquid polymer that wicks into thin openings using capillary action, where it then dries to provide a clear seal.
 This stuff is quite amazing! I tested it to see if it would work on weeping fuel tank leaks on wet wing aircraft. Though I never used it as such (wouldn't be "legal"), it did pass my tests. To test it I used to plastic orange juice bottles, drilled a small hole in the bottom and also made a razor cut about and inch long. Applied CTCCS and allowed to dry overnight.
 In filled one bottle with Avgas and the other with auto gasoline. Both showed no signs of leakage after a week.
 Once dry, CTCCS remains flexable so should work as a sealant on our LD seams for many years.

bumper
bumper
"Yonder" '05 MB
"WLDBLU" glider trailer
Re: Finding leaks or look at all the bubbles
Reply #2 –
Yahoo Message Number: 119537
I have used this, and agree it works very well. However, it has extremely low viscosity so is not a 'gap filler'. It works best on minute gaps so the capillary action can work effectively. On the LD, crimped metal and windshield seals will respond well.

Steve
2004 FL
2013 Honda Fit
Re: Finding leaks or look at all the bubbles
Reply #3 –
Yahoo Message Number: 119538
"From a design perspective, many of those air leaks, such as the side body horizontal seams, would not concern me. While air might work its way down and out such a seam, water is not likely to enter and move up the seam to get inside."

Ken
 If the side of the motor home is exposed to a hard, wind driven rain, it could, and in case did, penetrate a leaky seam. I had previously disassemble the interior nose area to repair water-caused rot damage. There were obvious signs of leakage in the area where one of the major bubbles occurred. If the seams were Factory sealed, it is possible that the sealant had broken down due to effects of time and/or of years of operation. The exterior side and nose connection had be worked on by a previous owner who failed to correct what appears to have been a long-term problem. The seam may have been able to move, breaking the seal.
 I'm familiar with the door adjustment after a long talk with LD's Steve about the problem. LD's straightening method has been discussed here several time in the past.
Even with a well adjusted door, serious air leaks are a very common complaint.
A couple of weeks ago, while camping on the coast during one of the more powerful storms, our LD was exposed to strong winds on the passenger side of the rig. Around the edges of the coach door came a continuous stream of cold air, without any water. Many hang a blanket over the interior door opening to limit air intrusion and drafts.  A search of he archives will confirm this.
Most LD doors have been slammed open by the wind a few times, bending the door.  After a straightening or two, it become next to impossible to get the door perfectly straight again. The rubber weatherstripping isn't very thick and usually loses much of its resiliency after a few years, permitting gaps between the two strips of weatherstripping.
 The rear corner posts are made of wood, covered by the corner caps.  Once they are wet for an extended period, they will rot. My brother's best friend inherited an older T/K with such damage. We attempted to repair it but the damage was so extensive that it was sent the wrecking yard so beware.
A rig that is keep well sealed should not be bother by this problem.
 Moisture buildup is a problem in homes and RVs and each has various means of ventilation.
Modern, tightly sealed homes use air-to-air heat exchangers to control moisture and to provide fresh air. RVs use the windows and vents to ventilate, not air leaks through the walls.
All the leaks I sealed were seams and end caps, none of which should not have been present since any water entry would result in wet wood.

Larry
2001 MB
* Not to be confused with Larry W (3000 of my posts are actually from expert Larry W due to Yahoo transition mis-step)
Re: Finding leaks or look at all the bubbles
Reply #4 –
Yahoo Message Number: 119539
"Good job! This is an applicsation that is well suited for (don't laugh) "Capain Tolley's Creeping Crack Seal" (CTCCS)!!"

bumper
 I too am a long-term user and fan of Captain Tolley's. I have used to fix all sort of leaks in RVs, kayaks and marine electronics.
http://www.captaintolley.com/index.html>
 I used it a few years ago to seal a badly cracked front cap on an LD that had hit a tree branch. I drilled a small hole in the interior paneling so the owner could keep an eye on it during the rainy season.
It was a lot simpler than either patching the exterior or removing the interior paneling and patching it from inside.
It only works where the crack(s) fits tightly together.

Larry
2001 MB
* Not to be confused with Larry W (3000 of my posts are actually from expert Larry W due to Yahoo transition mis-step)
Re: Finding leaks or look at all the bubbles
Reply #5 –
Yahoo Message Number: 119542
Very Interesting stuff. It says its paintable, but it also warns against polypropylene and polythene plastics. Has anyone tried it on the plastics used on endcaps and taillight sections with success? Lydia
Lydia.
Current: 2020 JLUR w 15’ Squaredrop
Former: 2006 30IB Anniversary Edition
Re: Finding leaks or look at all the bubbles
Reply #6 –
Yahoo Message Number: 119544
"Very Interesting stuff. It says its paintable, but it also warns against polypropylene and polythene plastics. Has anyone tried it on the plastics used on endcaps and taillight sections with success?"

Lydia
 While Captain Tolley's would probably work for the narrow spaces in the seams, it would not work filling the large gaps that appear on the end caps. Since it is very thin and runny, a large amount of it would be necessary to seal the seams, since most of it would run out and need to be wiped up.
Instead, I used DAP 3.0 crystal clear sealant to seal the seams and the end caps.
http://www.dap.com/3point0/all_purpose.html> It works well in applications where a white sealant would cosmetically be inappropriate. My preferred sealant is 3M's 5200 marine polyurethane but it is not available in a clear color.
 Since the seams and end caps are painted in both white and the color of the motorhome, a clear sealant is required to look correct.
To get good penetration in the seams, I applied masking tape to both side of the seams, leaving a 1/4" gap to expose the seam. A bead of the the Dap 3.0 was applied to each seam and then forced into the seam using a gloved finger. The masking tape contains the excess sealant, leaving a clean surface when the tape is removed.
The end caps required a thicker bead that was also forced deep into the gap. Many sections of the rear end caps needed two applications to to totally fill the wide gaps.
 Proper preparation is needed to insure that the sealant does its job.
The entire rig was wash and dried. Compressed air was used to blow out the seams and then left to completely dry. The end cap gaps were cleaned and scraped to removed any loose paint and old sealant and to provide a place for the sealant to be placed.
 During the pressure testing, large bubbles appeared around the rooftop A/C unit. Water leakage A/C had not been a problem so I assumed the air leaked from the top of the roof gasket. The interior A/C trim was removed and the three bolts securing the A/C unit were tightened. They were very loose.

Larry
2001 MB
* Not to be confused with Larry W (3000 of my posts are actually from expert Larry W due to Yahoo transition mis-step)
Re: Finding leaks or look at all the bubbles
Reply #7 –
Yahoo Message Number: 119545
Quote
In an attempt to pinpoint a hard to find leak in an mature LD, I >recently used about 300' of 2" wide masking tape to seal all the >exterior openings including the doors, windows, stove fan vent, >escape hatch and

A very strong soapy water solution was brushed over the exterior Bubbles appeared in dozens of places along the horizontal and >vertical seams and end caps.
 After seeing so many bubbles in the rear end caps, I now know why >the rear columns in older MBs and T/Ks are subject to rotting.
If these seams have opened up on your LD, do not assume that they >are still water tight.
Hi Larry,

Fantastic post and something to really think about! Great work!

A couple of questions though: You specifically mention older Midbaths and Twin Kings, is the construction of those floorplans different than the others?
 Next, are you tempted to peform the leak test on a newer rig such as your own? It would be interesting to learn if air leaks are the nature of the beast.
 I've always wondered about what affect all the expansion and contraction our rigs go through with temperature changes, does to the integrity of the coach framing and the window seals. Also find myself wondering what the LD factory's reaction is to this subject.

Thanks for sharing your findings.
Steve K. (watching the snow pile up in Ohio)
Steve K

2003 Mid-bath
Re: Finding leaks or look at all the bubbles
Reply #8 –
Yahoo Message Number: 119546
Larry's post about seam leaks has piqued my interest (In fact, I learn something from almost all of Larry's posts).
 My 2003 (bought in July '10) has cracks and gaps all over it along the seams.  I haven't seen any evidence of leaks, but I'd like to get on top of things before I do.
 The front passenger side looks like it has had some work done previously.  There are screws from top to bottom on both sides, and the sealant is different than what I see everywhere else.

I briefly asked the factory what they thought and the answer was: (a) they didn't do the screw repair - someone else much have (b) adding screws is not recommended (c) my 2003 was sealed with a tape that isn't used anymore (d) The wood under the seams is sealed at the factory and water that enters should exit out the bottom.
(e) It's not a bad idea to caulk the seams with polyurethane as a form of extra insurance
 I know I've seen some (most) of this advice communicated here in that past.
 My plan is to dry, clean, and caulk these seams once I get a couple of warmer days.
 I posted a series of pictures in case anyone want to visualize what I'm talking about or offer any suggestions: http://picasaweb.google.com/109252498480178033803/LDSeams03MB?feat=directlink 
Rich '03 MB
2003 MB
Re: Finding leaks or look at all the bubbles
Reply #9 –
Yahoo Message Number: 119547
"You specifically mention older Midbaths and Twin Kings, is the construction of those floorplans different than the others? Next, are you tempted to perform the leak test on a newer rig such as your own?"

Steve
 I mentioned the MBs and T/Ks because they are the floor plans I have seen rot in. There is no reason why this problem would be limited to them but I can only report what I have seen.
The rear end caps seem to open up on all models and it be wise for all owners to keep an eye on their rigs, sealing any new gaps that open.
http://www.flickr.com/photos/lwade/sets/72157623383483881/>
 After seeing the air leaks in this older LD, I would like to see how our 2003 LD would do. It will be a while before this happens since it is an big job, taking several hours to take all the openings.
 Since the Factory does not participate or even acknowledge this forum's existence, I'm clueless on their response.
I suspect they would shrug and say it happens and to come on in for a reseal...at a healthy fee. I know members on this forum that have had the caps resealed and it wasn't cheap

Larry
2001 MB
* Not to be confused with Larry W (3000 of my posts are actually from expert Larry W due to Yahoo transition mis-step)
Re: Finding leaks or look at all the bubbles
Reply #10 –
Yahoo Message Number: 119548
"I briefly asked the factory what they thought and the answer was: (a) they didn't do the screw repair - someone else much have (b) adding screws is not recommended (c) my 2003 was sealed with a tape that isn't used anymore (d) The wood under the seams is sealed at the factory and water that enters should exit out the bottom.
(e) It's not a bad idea to caulk the seams with polyurethane as a form of extra insurance"

Rich
 Interesting that the Factory said they would not use screws when our 2003 LD has three Factory installed screws at the bottom of each rear end cap.
You could re-glue the cap and use screws to pull the cap back into place until the adhesive cures and then remove the screws. That might be a better solution since the caps often crack around the screws.
There is a lot of stress applied to the caps, both from the twisting and flexing that the body goes through while on the road, not to mention the thermal expansion and contraction forces.
I'm amazed the body doesn't pop apart at the corners.
LD builds a strong body that stays that way unless the wood frame gets and stays wet, allowing rot to weaken the structure.
Our responsibility is to make sure water does not get in.
 LD changed to a different adhesive tape somewhere around 2004 or 2005 that is supposed to hold up better. Time will tell.

Larry
2001 MB
* Not to be confused with Larry W (3000 of my posts are actually from expert Larry W due to Yahoo transition mis-step)
Re: Finding leaks or look at all the bubbles
Reply #11 –
Yahoo Message Number: 119549
Quote
Interesting that the Factory said they would not use screws when our 2003 LD has three Factory installed screws at the bottom of each >rear end cap.
In the interest of clarity, the factory said that _I_ should not use screws.  I can understand why they might say that to someone they don't know on the other side of the country (me).
 As far as the extra screws already on my coach, the screws heads exactly match the paint scheme and are identical to the screws on the cab over  seams.  Who knows?  Based on the little bit of history I have from the previous owners, I still think there's a good chance that the screws were installed at the factory.
 I hope they're right regarding the amount of sealant protecting the wood underneath the caps.  I'll be doing what I can to make sure water doesn't get that far, just in case.

Rich
2003 MB
Re: Finding leaks or look at all the bubbles
Reply #12 –
Yahoo Message Number: 119551
wrote: As far as the extra screws already on my coach, the screws heads exactly match the paint scheme and are identical to the screws on the cab over seams. Who knows? Based on the little bit of history I have from the previous owners, I still think there's a good chance that the screws were installed at the factory.
--- One indication that some post-construction sealing (and screws added) may have been done at the factory is that the photos of your 2003 show the "wrap band" over the seam of the rear end caps. My rig was delivered in November of 2003, and it did *not* have the end cap bands as OEM; I had them put on later, but I think that these bands became standard with the 2004 models.  Some earlier "2003" models have the lapped end caps, i.e., the top part of the wrap laps over the bottom part of the wrap.
 Also, I think that my 2003 TK has a different original screw pattern on the corner wraps at the front edges of the box than Larry's 2003 FL/FD. Your 2003 MB end cap screws might well be from the original manufacture, and LD doesn't "remember" installing them in those particular locations; in my experience, LD's "what and when" recall  can be variable.  ;-)

Joan
2003 TK has a new home
Re: Finding leaks or look at all the bubbles
Reply #13 –
Yahoo Message Number: 119554
The references to tape made by Larry and  Ed are to tape that is used to cover the wood framing that is no longer accessible, right? That is, there's nothing that should be done from a maintenance standpoint with tape?
 Does anyone have experience with a good brand of polurethane for caulking the seams?

Thanks

Pete Bateman
Re: Sealant for seams
Reply #14 –
Yahoo Message Number: 119555
Quote
"...Does anyone have experience with a good brand of polurethane for caulking the seams?"

Thanks

Pete Bateman in Albuquerque

 As Larry said in an earlier message:  "Instead, I used DAP 3.0 crystal clear sealant to seal the seams and the end caps."

Chris
Formerly: 2002 30' IB
Re: Finding leaks or look at all the bubbles
Reply #15 –
Yahoo Message Number: 119556
I can't speak for anyone else, but I was talking about a 2-sided tape used to stick the end caps to the AL siding.  The tape didn't work well (hence, the problem) and LD doesn't use it anymore.
 From what I understand (as explained to me, not seen with my own eyes), there is an additional layer of sealant under the end caps that protects the wood if any water does get under the seam caps.    Larry's bubble test offered evidence that this method (if it was even used with that vintage) can fail over time.
 A failure isn't surprising to me given the nature of caulk, the age of the coach
2003 MB
Re: Finding leaks or look at all the bubbles
Reply #16 –
Yahoo Message Number: 119557
"The references to tape to tape that is used to cover the wood framing that is no longer accessible, right? That is, there's nothing that should be done from a maintenance standpoint with tape? Does anyone have experience with a good brand of polyurethane for caulking the seams?"

Pete
 LD uses a double-sided adhesive tape to attach the caps. If the tape releases, the two repair choices are to either remove the cap and replace the tape (LD uses a better tape now) or to pull the loose part of the cap back and  glue it back into position.
Replacement is an expensive fix since often new caps are needed, requiring repainting.
 Many times, in past postings, I have recommended 3M 5200 Fast Cure Polyurethane sealant having used it for twenty years, in both RV and marine applications, without failure. It sticks tenaciously to most clean surfaces and is available at most home centers (Lowes and HD) 3M 4000 is also good but is normally only available at marine hardware stores 3M 5200's downside is white is the only color available. White doesn't look right when filling gaps on the end caps since the caps are two-tone. If the cap can be pulled back, 5200 can be injected under the cap, with the squeeze out controlled with masking tape.
 To fill gaps in the  caps, with cosmetically pleasing results, a clear sealant is needed. I have used two different clear sealants. They are Dap 3.0 Advanced all-purpose sealant-crystal clear and Sashco's Big Stretch- clear.
http://www.dap.com/3point0/all_purpose.html>
http://www.sashcosealants.com/Contractors/Big_Stretch.aspx> I cannot report on long-term performance on either since I only have used them for a few years.
I used to buy Big Stretch at a local paint store but the store is no longer in business. I do not like buying sealant online due to the expense and difficulty in returning defective product, usually older stock.
The Dap 3.0 is available at Lowes and the stock turns over quickly so you are likely to get fresh product.

Larry
2001 MB
* Not to be confused with Larry W (3000 of my posts are actually from expert Larry W due to Yahoo transition mis-step)
Re: Finding leaks or look at all the bubbles
Reply #17 –
Yahoo Message Number: 119558
"From what I understand (as explained to me, not seen with my own eyes), there is an additional layer of sealant under the end caps that protects the wood if any water does get under the seam caps"

Rich
 LD has used various coating on the wood under the caps to prevent water damage in case of leakage. It evidently has not been completely successful.
LD still uses some type of double-side adhesive tape, the latest and greatest supposedly failure-proof.
 In LD's defense, they  recommend a Factory resealing after ten years or so of ownership.
How many of you with 10+ year old rigs have done that?...that's what I thought.

Here is another way to keep your rig leak free.
http://www.coversuperstore.com/Polytuf-Blue-Poly-Tarps/>

Larry
2001 MB
* Not to be confused with Larry W (3000 of my posts are actually from expert Larry W due to Yahoo transition mis-step)
Re: Finding leaks or look at all the bubbles
Reply #18 –
Yahoo Message Number: 119565
Hello, Pete.
 You asked if, under those end caps, the wood framing is covered.  The answer is perhpas yes, perhaps no.  Those Lazy Daze built before 2000 may or may not have sealant applied under the end caps that covers all of the wood structure surface.  That means, if the end cap attachment (for example, VHB Tape Bonding) fails just a little, wood structure under the end cap will get wet. The end cap disbonding subject is a bit complex.  Please see new message I've posted today on the subject.

Don McGlothlen EZ-2001 LD MB
 
Finding leaks or look at all the bubbles
Reply #19 –
Yahoo Message Number: 119535
From a design perspective, many of those air leaks, such as the side body horizontal seams, would not concern me.  While air might work its way down and out such a seam, water is not likely to enter and move up the seam to get inside.
 As to the coach door, it took me a year and a call to the mother ship to learn how to close mine.  The door has a slight bow in it and will not close fully just by slamming it.  Less speed and pressure, but continuous pressure as it closes does the trick.  Even then, I am sure some air infiltration can occur.  Water does not get in.
 Not knowing the physical construction behind the corner posts, I don't know whether I would be concerned about air leaks there.  As long as water cannot get in, I would be OK with air getting out.
 Houses that are too "tight" have been found to be unhealthy.  Some degree of air movement into and through a living space is a good thing to have.  Any wall space will gather dampness from our cooking, exhalations, showers, etc., as moist warm inside air meets cooler wall surfaces.  Condensation is the result.  Homes are built with a vapor barrier on the inside to manage such air movement so that it is not getting to the insulation.  Sealing every pore on the exterior of our LD's would be like putting a vapor barrier on the outside of a house - a certain way to destroy the insulation and rot out a house.
 The pressurization and soapy water idea is a great one.  Just be careful about how much you try to seal.  Do so judiciously.

Ken F in NM
'08 MB