Plastic doghouse covers and fire oh my....

[bkahler]

Originally Posted by PeterH-350LE

Keep the clearance, with the cover being metal you want lots of fireproof insulation and sound proofing

The reason for trying to use metal is to hopefully reduce the amount of fireproof insulation required. I still plan on using insulation but until I know how much this thing is going to weigh I won't know which approach to take.

I've got a small 50 lb scale somewhere in my shop. If I can find it I'll weight all the metal pieces. That should give me a good idea of what it's going to weigh.

[kidjedi]

Coupla things...

I did my GMC engine cover today. That Thermo-tec stuff from Summit is great (as long as it does what is advertised). I may even skip the ceramic fiber blanket layer, knowing I've got every layer of plywood completely encapsulated with this stuff, and it's supposed to withstand temps of 2000F. though... I just rechecked that, and even though the Summit website says it will withstand "ambient temps" of 2000 degrees F, there is a response from a seller on Amazon that says "In addition to the polyethylene film, the foil surface provides direct protection from radiant heat up to 2000 Deg F and direct temperatures up to 300 Deg F." Who knows what that really means, so now I'm rethinking the fiber blanket yet again.

Regarding the metal dog house... just wanted to point out that "used up" stainless steel grills are very cheap and easy to come by. I can get them at a local salvage place for $25-50 all day long. I made the AC shroud on my Argosy out of one (barely had to do anything), but it might also be a good source for stainless to use for a dog house cover.

EDIT: sometimes restaurant prep tables are cheap too. I've cut a lot of stainless panels out of old restaurant tables I've picked up for $25-$30.

[bkahler]

Originally Posted by kidjedi

Coupla things...

I did my GMC engine cover today. That Thermo-tec stuff from Summit is great (as long as it does what is advertised). I may even skip the ceramic fiber blanket layer, knowing I've got every layer of plywood completely encapsulated with this stuff, and it's supposed to withstand temps of 2000F. though... I just rechecked that, and even though the Summit website says it will withstand "ambient temps" of 2000 degrees F, there is a response from a seller on Amazon that says "In addition to the polyethylene film, the foil surface provides direct protection from radiant heat up to 2000 Deg F and direct temperatures up to 300 Deg F." Who knows what that really means, so now I'm rethinking the fiber blanket yet again.

Regarding the metal dog house... just wanted to point out that "used up" stainless steel grills are very cheap and easy to come by. I can get them at a local salvage place for $25-50 all day long. I made the AC shroud on my Argosy out of one (barely had to do anything), but it might also be a good source for stainless to use for a dog house cover.

EDIT: sometimes restaurant prep tables are cheap too. I've cut a lot of stainless panels out of old restaurant tables I've picked up for $25-$30.

Not sure about using stainless for a doghouse cover. Stainless steel is heavier than carbon steel and aluminum, with the lowest strength-to-weight ratio. It's also possible for stainless to release chromium fumes at high temperatures. Not sure I'd want to use it as a fire barrier.

The fiber blanket does sound like the best option. I think Peter's description of what he did points to a better sound and engine heat experience.

I'm curious as to what the seller means when they say "direct temperature"?! Sounds like seller mumbo jumbo

[kidjedi]

Originally Posted by bkahler

Not sure about using stainless for a doghouse cover. Stainless steel is heavier than carbon steel and aluminum, with the lowest strength-to-weight ratio. It's also possible for stainless to release chromium fumes at high temperatures. Not sure I'd want to use it as a fire barrier.

Good information. I figured if they were using it to literally contain fire (the grill hood), it would be a good choice, but maybe not.

Originally Posted by bkahler

I'm curious as to what the seller means when they say "direct temperature"?! Sounds like seller mumbo jumbo

Right. But also a good reminder that even though we see things written in the item description, who knows what the "truth" is. I bought this stuff because Summit (and others) advertised a 2000F max temp, but if the "direct contact" temp is only 300F, then it's the same as all the other butyl mats. It's around the same price as Kilamat, so I didn't get fleeced or anything (and with the Summit buy-one-get-one when I bought, I think I actually came out quite a bit ahead). I also like that it's a large sheet, not a bunch of tiny ones. But the discrepancies in the item descriptions is definitely something to think about.

[bkahler]

I finally started assembling the metal doghouse cover this afternoon. I'm going to build one and make sure it fits my Argosy and my old 310. Assuming it fits both I'll fabricate the second one.

First thing I did was to weigh the metal pieces that will make up one cover assembly. That came to about 27 lbs.




I then weighed the bare plastic doghouse cover and it came to 10 lbs.




If I remember right Peters completed cover weighed in at around 27 lbs so right off the bat the steel cover is starting at a disadvantage!

I'm thinking about how to make it easier to lift the steel cover and my first thought was to have a couple of hinged handles, one on each side to help lift the housing. One thing I found while handling the original cover it was a little awkward to lift and move around the cockpit due to no handles. With luck maybe handles will help that process somewhat.

Here's a few pictures of where I'm at so far.






I need to trim the sides to follow the correct upward angle but first I need to tweak the angle upward slightly. The panel as bent by the fab shop is off by about one degree and I didn't catch it before I started welding. That 1 degree equated to about 1/2' difference on the side where the angle meets the flat bottom near the curved corners.






Also, the curved panels as delivered by the fab shop are about 1" short overall on the circumference so I will need them to make four more corners. The curved panels they made are the correct radius, they are just to short.

[PeterH-350LE]

Originally Posted by bkahler

......

First thing I did was to weigh the metal pieces that will make up one cover assembly. That came to about 27 lbs.

I then weighed the bare plastic doghouse cover and it came to 10 lbs.

If I remember right Peters completed cover weighed in at around 27 lbs so right off the bat the steel cover is starting at a disadvantage!

...

So assuming, I started with the bare 10 lbs cover, I must have added ~17 pounds, which means that you could end up @~ 44 pounds, if you go through all the fire retarding padding extremes, I went through.

I hope your trans dipstick is in the front.

[bkahler]

Originally Posted by PeterH-350LE

So assuming, I started with the bare 10 lbs cover, I must have added ~17 pounds, which means that you could end up @~ 44 pounds, if you go through all the fire retarding padding extremes, I went through.

I hope your trans dipstick is in the front.

I don't think I need to worry as much about the fire retardant materials with the cover being steel. I think sound proofing and exterior covering will likely be what I'm going to be dealing with.

I think handles will make a big difference in removing and installing the cover.

[martin300662]

No sure if it applies with the later shape dog-house cover, but Bella's cover barely passes the seats when opening so adding any extra width for handles would be problematic.

[bkahler]

Readjusted the angle for the upper section and the fit seems to be very good. What's left to be done on this one is the front corners need to be fabricated and installed and the upper edges where the panel meets the top of the doghouse opening needs to be welded in place.

I weighed the cover along with the corner pieces and the weight looks like it's going to end up being 28 lbs.




You can see in this picture where the curved corner piece dimensions were way off as far as length goes. The curve is right, they were just made to short.





This week the panel will probably be test fitted on the 310 so that will tell me whether or not I fabricated the doghouse opening in the Argosy the same as the 310. Hopefully I'm close

Brad

[bkahler]

Originally Posted by martin300662

No sure if it applies with the later shape dog-house cover, but Bella's cover barely passes the seats when opening so adding any extra width for handles would be problematic.

That's one of the reasons I'm looking at folding handles. Also, these covers lift off instead of being hinged so that will hopefully alleviate that worry. I do have the drivers seat installed so that should provide some idea of what it will be like.

[bkahler]

Originally Posted by martin300662

No sure if it applies with the later shape dog-house cover, but Bella's cover barely passes the seats when opening so adding any extra width for handles would be problematic.

Originally Posted by bkahler

That's one of the reasons I'm looking at folding handles. Also, these covers lift off instead of being hinged so that will hopefully alleviate that worry. I do have the drivers seat installed so that should provide some idea of what it will be like.

Martin, I was thinking with the folding hinges it wouldn't be a problem, unfortunately the handles would be extended when going past the seats and once I thought about your question again I realized what you were getting at!

So I went down to the shop to see just how much clearance there was between the side of the doghouse cover and the seat. It looks like there is about 3" of clearance which should be more than enough for a fold out handle. The seat looks a little weird because I have it covered with plastic bags



Hopefully this means using handles won't be an issue in my installation. Here's a picture of the style of handle that I'm considering.

[PeterH-350LE]

Originally Posted by bkahler

I don't think I need to worry as much about the fire retardant materials with the cover being steel. I think sound proofing and exterior covering will likely be what I'm going to be dealing with.

I think handles will make a big difference in removing and installing the cover.

I like your handle design. Still concerned about heat transfer without added "fire resistant" insulation/soundproofing. Last thing I would want to do is create even more heat in the cab.

[bkahler]

Originally Posted by PeterH-350LE

I like your handle design. Still concerned about heat transfer without added "fire resistant" insulation/soundproofing. Last thing I would want to do is create even more heat in the cab.

I still plan to add fire resistant insulation. I just don't think I need to have excessive amounts of it due to having a steel cover vs plastic cover.

I think a layer of sound deadening matt and a layer of heat barrier should be sufficient.

I'm guessing that the overall weight of the cover will end up in the 35 lb range. With handles that should be manageable.

Something I have been considering, mostly as a "just in case" mental exercise, is hinging the cover at the top like the 74-76 Argosy doghouse covers were hinged. I would prefer not to do this but it certainly is an option. Possibly a hinge with quick disconnects to allow the cover to be lifted out of the way if need be.

With the existing plastic cover I found while working on the 310 over the years I would at times just lift the cover up and hold it while I looked at whatever I needed to look at under the hood, like the air cleaner, etc. Something I thought about doing but never did was to add a prop rod to hold the cover up so I wouldn't have to lift it out of the way to do a simple task like checking the transmission fluid.

I'm going to start fabricating the second cover later this week and will also try and get the curved panel sections remade before the end of the week.

[Air345Fly]

If you hinge the cover you could use gas spring rods to help
with the lift. You can get them in many different lengths
and with different lifting forces. They are pretty cheap too.

[dspaw]

this is an interesting subject - I need to rebuild or repair my doghouse cover as there is too much heat infiltration into the cab. And noise. The sound and heat deadening layers are a good start, but it seems I have sealing problems too.

I don't think the hinge/handle idea will work, unless the handles are removable and the doghouse can be removed from the hinge. Also skeptical about mounting of the lift assists.....but you guys are magicians.

[PeterH-350LE]

Originally Posted by bkahler

...

Something I have been considering, mostly as a "just in case" mental exercise, is hinging the cover at the top like the 74-76 Argosy doghouse covers were hinged. I would prefer not to do this but it certainly is an option. Possibly a hinge with quick disconnects to allow the cover to be lifted out of the way if need be.

With the existing plastic cover I found while working on the 310 over the years I would at times just lift the cover up and hold it while I looked at whatever I needed to look at under the hood, like the air cleaner, etc.....

One of my most favorite use of the cover is the ability to lay on it after moving it back 8-10inches. This gives me more comfortable access to everything unreachable in the front , like the belts, fan, etc etc. I would not want to give up the ability by hinging it in the front.

[bkahler]

Originally Posted by dspaw

this is an interesting subject - I need to rebuild or repair my doghouse cover as there is too much heat infiltration into the cab. And noise. The sound and heat deadening layers are a good start, but it seems I have sealing problems too.

I don't think the hinge/handle idea will work, unless the handles are removable and the doghouse can be removed from the hinge. Also skeptical about mounting of the lift assists.....but you guys are magicians.

Not sure why the handles would need to be removable when they would just fold down out of the way.

Hinging would be neat but would likely be more of a hindrance than a benefit in the long run. Possibly a hinge that isn't captive would be a possibility. The ability to lift the cover off and out of the way is important especially when working towards the front of the engine.

I'm considering prop rods of some sort that could hold the back end of the cover up to allow for easy checking of transmission oil and engine oil since I don't have the front mounted dipstick. The rods would then just lay down out of the way. The original 74 doghouse cover had just such a prop rod that seemed to work well.

If gas cylinders could be set up such that they can slip off their pivot points for complete removal of the cover then I can see where they might be useful. Using gas cylinders would require the front edge to be captured somehow so it could act like a pivot point but still allow the cover to be lifted off.

With prop rods instead of gas cylinders you don't really need a hinge because you can just use the front most edge as a pivot point. I do that now when lifting the plastic cover to look at the engine.

[bkahler]

Originally Posted by PeterH-350LE

One of my most favorite use of the cover is the ability to lay on it after moving it back 8-10inches. This gives me more comfortable access to everything unreachable in the front , like the belts, fan, etc etc. I would not want to give up the ability by hinging it in the front.

Agreed. I used to lay on the 310 cover like this all the time while working on the engine. Made for a nice little platform to lay on.

[dadstoy]

Originally Posted by PeterH-350LE

One of my most favorite use of the cover is the ability to lay on it after moving it back 8-10inches. This gives me more comfortable access to everything unreachable in the front , like the belts, fan, etc etc. I would not want to give up the ability by hinging it in the front.

Peter, you mean like this?

[PeterH-350LE]

Originally Posted by dadstoy

Peter, you mean like this?

Yes, Dean, but you are cheating, because you have the model with the metal plate you can remove.
The later models do not have that luxury.