Plastic doghouse covers and fire oh my....

[bkahler]

I'm starting this thread in the Classic's forum because Argosies have steel doghouse covers and Classic's (from 83 on?) have plastic doghouse covers.

If you haven't read about kidjedi's Argosy engine fire then you probably should.

One of our discussion points in his thread reminded me that Argosies had all steel doghouses whereas the Classic's had steel frames covered with a plastic lid. Thinking back on all of the Airstream motorhome fires that I have heard about or seen in person I don't recall hearing anything about Argosy fires, at least not catastrophic fires. So it would seem that a steel doghouse cover probably has something to do with that statistic.

Since I have an Argosy this should put me in the "safer" category, however several years ago as I was rebuilding my cockpit I used the doghouse assembly from the 345 that I dismantled. So, my Argosy has the plastic doghouse cover

Realizing this got me to thinking what I could do to replace and/or upgrade the plastic cover I now have. I was talking to a couple of co-workers who have years of experience around kilns and steam piping and they mentioned a product called Ceramic Fiber Insulation blanket. Doing a little research I found that these blankets in 1/2" thickness are good up to around 2300 degrees F.

Martin just made this comment in kidjedi's thread:

Originally Posted by martin300662

Although steel is massively better than plastic there are a whole range of fiber and resin materials now that are much better than steel.

Its totally possible to have a 'fiberglass' version made with fire retardant resins and graphite woven cloth, that simply will not burn at vehicle fire temps.

Then you need a lining that dissipates the heat before the interior catches from the temps coming through the doghouse.

To me this seems like a great idea if something was going to be produced in multiple copies. If someone wanted to take on a group build/buy doing something like this I would certainly be in.

However, the likely hood of that happening is probably on the low side so I'd like to explore other alternatives like the Ceramic Fiber insulation blanket, replacement steel covers or other possibilities.

My first thought for the Ceramic Fiber insulation blanket would be that just gluing it to the underside of the cover is probably not the best solution. My feeling is it will need to be structurally supported to keep it up against the cover by some mechanical means. What I've come up with so far is using flat metal straps bent to the shape of the underside of the cover that sandwich the Ceramic blanket between the strap and the cover. This would likely require mechanical fasteners through the cover to the straps.

Replacement steel covers would not be a difficult option for some people and more difficult for others. In my mind probably the biggest issue with switching to a steel cover would be the overall weight. The beauty of the plastic covers is how easy they are to remove and replace. An all steel cover obviously negates (at least to some extent) that advantage.

Anyway, I'd like to hear thoughts and ideas from others. I'm sure there will be no "one size fits all" solution but the idea of another one of these rigs burning up because of a piece of plastic is just a little unsettling to me.

Thoughts anyone?


Brad

[martin300662]

Originally Posted by bkahler

I'm starting this thread in the Classic's forum because Argosies have steel doghouse covers and Classic's (from 83 on?) have plastic doghouse covers.

If you haven't read about kidjedi's Argosy engine fire then you probably should.

One of our discussion points in his thread reminded me that Argosies had all steel doghouses whereas the Classic's had steel frames covered with a plastic lid. Thinking back on all of the Airstream motorhome fires that I have heard about or seen in person I don't recall hearing anything about Argosy fires, at least not catastrophic fires. So it would seem that a steel doghouse cover probably has something to do with that statistic.

Since I have an Argosy this should put me in the "safer" category, however several years ago as I was rebuilding my cockpit I used the doghouse assembly from the 345 that I dismantled. So, my Argosy has the plastic doghouse cover

Realizing this got me to thinking what I could do to replace and/or upgrade the plastic cover I now have. I was talking to a couple of co-workers who have years of experience around kilns and steam piping and they mentioned a product called Ceramic Fiber Insulation blanket. Doing a little research I found that these blankets in 1/2" thickness are good up to around 2300 degrees F.

Martin just made this comment in kidjedi's thread:



To me this seems like a great idea if something was going to be produced in multiple copies. If someone wanted to take on a group build/buy doing something like this I would certainly be in.

However, the likely hood of that happening is probably on the low side so I'd like to explore other alternatives like the Ceramic Fiber insulation blanket, replacement steel covers or other possibilities.

My first thought for the Ceramic Fiber insulation blanket would be that just gluing it to the underside of the cover is probably not the best solution. My feeling is it will need to be structurally supported to keep it up against the cover by some mechanical means. What I've come up with so far is using flat metal straps bent to the shape of the underside of the cover that sandwich the Ceramic blanket between the strap and the cover. This would likely require mechanical fasteners through the cover to the straps.

Replacement steel covers would not be a difficult option for some people and more difficult for others. In my mind probably the biggest issue with switching to a steel cover would be the overall weight. The beauty of the plastic covers is how easy they are to remove and replace. An all steel cover obviously negates (at least to some extent) that advantage.

Anyway, I'd like to hear thoughts and ideas from others. I'm sure there will be no "one size fits all" solution but the idea of another one of these rigs burning up because of a piece of plastic is just a little unsettling to me.

Thoughts anyone?


Brad

I think I have seen that ceramic fiber mat, with a aluminum woven clothe facing - basically to keep it clean and 'together', its sometimes sold as fire blanket. That also means it would be kept relatively clean if attached to the inside of the doghouse almost like under hood soundproofing.

Heck even if the adhesive let go in case of fire, it would act as a fire blanket!

[bkahler]

Just found this product, Colloidal Silica Rigidizer - Coating for Refractory Ceramic Fiber Products - 1 Quart. I wonder how well it would work on the inside of an engine compartment?

[ITSNO60]

I have some experience with the ceramic blanket and refractory cement, I've used Kaowool to line my propane forge and covered it with refractory cement. Some guys leave it raw but it gradually gets torn up when using the forge, I chose to cover mine with about 1" of refractory which has worked very well, however the refractory does add considerable weight and in an application like yours I am not sure if it wouldn't crack over time from it's own weight and bumpy roads etc. It is pretty tough though and I think if you put it on fairly thin over the blanket it might be OK, but you still might need some sort of support to keep the whole thing from dropping down even though the cement was quite sticky and in my forge, once cured, it hasn't the slightest hint at coming down from the ceiling, but my forge just sits in one spot and doesn't get shook around although it gets mighty hot, in the neighborhood of 2,500F. Keep in mind the refractory cement is supposed to be cured with heat and cooled very slowly, I baked mine somewhere around 800F if I recall and gradually decreased the temperature over 12 hours and got no cracking at all. After about 4 years of use still no cracks. You can see that the fire brick I used for doors did crack but not the cement.


Have you considered just lining it with tin?

[ITSNO60]

I think I would just line it with some tin and keep a fire extinguisher bolted to a convenient spot. Most engine fires are from fuel leaks so keeping the fuel system tight and making sure the rubber parts are not allowed to get old would be a priority.
I do know of a couple who had a fuel leak on their VW van with the Porsche engine while climbing a grade on I-8, by the time they noticed something was wrong it was all they could do to just get to the side of the road and get out, they could not save their suitcases or anything else it went up so fast.
Are you one of those guys like me who notices all the spots on the side of the road where a vehicle burned?

[ITSNO60]

In my first post I was referring to refractory cement but I see you were looking at rigidizer which is a better idea. I have not used it but a lot of guys do and supposedly it helps keep the blanket from getting torn up with use and keeps fibers from coming loose and floating around. Maybe that is a good option for you, not as protective as refractory cement but you may not need that, plus you won't have to deal with the weight.

[martin300662]

Just surfing for options, and some of the under hood/bonnet solutions have high temp resistance?

https://www.carinsulation.co.uk/prod...van-insulation

[PeterH-350LE]

Excellent Thread!
The foam on my cover has been an annoyance since day 1 and now i am double motivated to replace it. We all know the space is limited to thickness in several places, like the air cleaner. The old fiber glass insulation will act as a great guide.
With all the great info from you guys, my plan is to get

1. Brads high temp blanket, most likely the 1" version,

2. Martin's Thermal insulation, however without the fiber glass. I have some in the shop and need to source it again. Its only 1/8 thick. It will act as the keeper of the blanket and added sound proofing

3. something like heavy duty chicken wire, that s flexible enough to keep everything in place.
4. a handful stainless small bolts/nuts with big washers to keep the wire in place. So what if there are some bolt heads on the outside of the cover, may even recarpet it to hide them
thoughts/suggestions?

[bkahler]

Originally Posted by PeterH-350LE

Excellent Thread!
The foam on my cover has been an annoyance since day 1 and now i am double motivated to replace it. We all know the space is limited to thickness in several places, like the air cleaner. The old fiber glass insulation will act as a great guide.
With all the great info from you guys, my plan is to get

1. Brads high temp blanket, most likely the 1" version,

Since mine cover is custom installed I don't remember how much room I left for clearance above the air cleaner. That will dictate what I can or can't use.

2. Martin's Thermal insulation, however without the fiber glass. I have some in the shop and need to source it again. Its only 1/8 thick. It will act as the keeper of the blanket and added sound proofing

I need to look closer at the insulation Martin is referring too. Sound proofing is obviously still much needed although I think I read somewhere that the Ceramic blanket also provides some sound deadening properties.

3. something like heavy duty chicken wire, that s flexible enough to keep everything in place.

You might consider using Expanded metal.

It's stiffer than chicken wire and doesn't really weight all that much plus it's available in a variety of sizes.


I do want to look closer at Colloidal Silica Rigidizer. Possibly spray it with this stuff and then cover it with some of the sound deadening product that Martin mentioned.

4. a handful stainless small bolts/nuts with big washers to keep the wire in place. So what if there are some bolt heads on the outside of the cover, may even recarpet it to hide them
thoughts/suggestions?

Figuring out how to make the bolt/screw heads look decorative could be a challenge but worth it in the long run.

[bkahler]

Originally Posted by martin300662

I think I have seen that ceramic fiber mat, with a aluminum woven clothe facing - basically to keep it clean and 'together', its sometimes sold as fire blanket. That also means it would be kept relatively clean if attached to the inside of the doghouse almost like under hood soundproofing.

Heck even if the adhesive let go in case of fire, it would act as a fire blanket!

Do have a link I could look at?

[bkahler]

Originally Posted by martin300662

Just surfing for options, and some of the under hood/bonnet solutions have high temp resistance?

https://www.carinsulation.co.uk/prod...van-insulation

My guess is this is what you were referring to above!

Lots of good ideas coming out in this thread so far.

[bkahler]

Originally Posted by ITSNO60

In my first post I was referring to refractory cement but I see you were looking at rigidizer which is a better idea. I have not used it but a lot of guys do and supposedly it helps keep the blanket from getting torn up with use and keeps fibers from coming loose and floating around. Maybe that is a good option for you, not as protective as refractory cement but you may not need that, plus you won't have to deal with the weight.

I kinda figured you were referring to a cement type of product! Thanks for the feedback on the rigidizer. I'm tempted to order a can of it just to see what it's like after spraying. In the long run the cost to try would be negligible compared to the cost of replacing a motorhome.

Thanks!

[martin300662]

Originally Posted by bkahler

Do have a link I could look at?

Sorry Brad, I was just flicking through images and didn't take note of the actual link....

Will do better next time!

[bkahler]

I found the following information about Colloidal Silica Rigidizer. Sure looks like it has potential for use on the doghouse covers.

For application it can be brushed, rolled or sprayed. Apparently a regular water spray bottle works for spraying.

Temperature Rating: 2600℉

Benefits
Increases surface hardness of ceramic products.
Easily applied by brushing, rolling, dipping, or spraying.
Reflects heat and thermal shock resistant.
Bond composites and laminates.
Increases resistance to erosion of high velocity gases.

Applications
Surface coating for ceramic products exposed to high velocity gases or flame impingement.
Adhesive for use in making composites and laminates.
Adhesive for ceramic blanket and paper.
Catalytic converter mat protection.
Surface treatment for vacuum formed shapes to increase surface hardness.
Veneering Modules over Refractory.
Attaching Boards to Furnace Shell.

[Travel Pro]

Originally Posted by ITSNO60

I think I would just line it with some tin and keep a fire extinguisher bolted to a convenient spot. Most engine fires are from fuel leaks so keeping the fuel system tight and making sure the rubber parts are not allowed to get old would be a priority.
I do know of a couple who had a fuel leak on their VW van with the Porsche engine while climbing a grade on I-8, by the time they noticed something was wrong it was all they could do to just get to the side of the road and get out, they could not save their suitcases or anything else it went up so fast.
Are you one of those guys like me who notices all the spots on the side of the road where a vehicle burned?

One of the problems with engine bays that are difficult to look into and through is that they don't get the frequent inspections they should have. Fuel fittings, hoses,etc. on older vehicles are always probable points of failure. Keeping them replaced as needed is important for fire prevention. Having said that, people might want to consider adding a fire suppression system. Really good ones run under a grand at sources like Summit Racing and they come in multi-delivery nozzles, remote activation by cable or electrical, and have sufficient volume to extinguish most fires. An additional benefit is that they are available in chemicals that do little or no damage to electrical/electronic components and offer easy cleanup. Automotive sound and heat suppression matting able to withstand around 1700 to 2500 degrees for short periods is also available reasonably from multiple automotive sources. This stuff comes in thicknesses as thin as 3/16 to 3/8 inches.
Just thinking out loud.

[bkahler]

Yep, fire suppression is definitely on the list of upgrades that are needed. In this thread I'm wanting to address the plastic doghouse cover that is used in the Classic motorhomes. Hoping to see lots of different ideas and thoughts on ways to improve and or replace the plastic cover.

The plastic doghouse issue is rather unique to the Classic's whereas fire suppression information can be found easily using a google search.

Also, addressing the causes of engine compartment fires is already well documented as well. I'd rather not have this thread go off on a tangent if possible.

[PeterH-350LE]

Ok, I am on it. I ordered a quart of Colloidal Silica Rigidizer and White Ceramic Insulated Baffle Blanket, 1 Roll = 24 Feet (300 inches) x 25 inches x 1 inch .
The expanded metal sheets are available in various sizes at Home Depot. I will report back once I start tackling this project hopefully this coming week.
Thanks all for the input and suggestions.

[bkahler]

Originally Posted by PeterH-350LE

Ok, I am on it. I ordered a quart of Colloidal Silica Rigidizer and White Ceramic Insulated Baffle Blanket, 1 Roll = 24 Feet (300 inches) x 25 inches x 1 inch .
The expanded metal sheets are available in various sizes at Home Depot. I will report back once I start tackling this project hopefully this coming week.
Thanks all for the input and suggestions.

Good. At the moment I don't have time to actually do any prototyping or tinkering. I need to get the replacement panels done so I can get the Argosy back outside!

Looking forward to seeing pictures.

[PeterH-350LE]

Originally Posted by PeterH-350LE

Ok, I am on it. I ordered a quart of Colloidal Silica Rigidizer and White Ceramic Insulated Baffle Blanket, 1 Roll = 24 Feet (300 inches) x 25 inches x 1 inch .
The expanded metal sheets are available in various sizes at Home Depot. I will report back once I start tackling this project hopefully this coming week.
Thanks all for the input and suggestions.

I also ordered a couple of bottles of this product:

Lynn high temp adhesive

• PRODUCT INFO: Sodium silicate solution, also known as waterglass, or liquid glass is a colorless water-based liquid. Dries to a clear solid form that can withstand temperatures up to 2000F
• USES: Commonly used as a high temperature adhesive for ceramic fiber blanket, boards and other refractories. Sodium silicate is also used in making pottery, ceramics, concrete sealing, automotive repair and fire protection.
• SIZE: 4 oz bottle

[Portage to Caravan]

I retired from the oil-chemical industry where I was employed to install Kaowool on piping and within furnaces, and I couldn't more highly advise against using it. If you breath any dust off of it the coughing fit that will ensue will make you wonder if you'll ever draw another clear breath. It is absolutely brutal, and silica has been found (or accused) of causing lung cancer. You need to take special precautions when using it.
There are other options available. Talk to someone at your auto suppy house about fire resistant fabric.

Jim