Community Forums

kartvines · 07-02-2011, 03:35 PM

I read a post here about how one of our member used reflective insulation bubble wrap to insulate the inside of his doghouse and being I still had a half of a roll from an earlier project, I decided it would be a good project to do today. Who wouldn't want to have it cooler and quieter right?

Now that I just finished the installation of the bubble reflective wrap , it made me wonder if the heat of the Chevy 454 engine would melt the plastic that is between the reflective foil?

I would hate to have it melt not only because of the odor, but the damage it could case to the engine and electrical components.

Do I now have to rip it all out agsin?

paz · 07-02-2011, 05:40 PM

Most bubble wrap is made of polyethylene, which melts at about 400ºF. Under-hood temperatures can reach 450 to 500ºF. The aluminized surface may provide some extra heat resistance, but if it were me, I'd rip it out.

A piece of ours came loose once and I finally saw it sitting on top of the engine. I'm glad it was non-flammable and not anything that could melt.

Camping World used to have a kit that had foil-backed fiberglass sheet, high-temperature aluminum tape and high-temperature adhesive. I haven't seen the kits for several years, but I heard somewhere that some hot rod shops may have heat-resistant insulation.

Ernie Ekberg · 07-02-2011, 06:02 PM

JC Whitney has the foil mylar insulation. I can't imagine the mess with plastic bubble wrap. You have a big investment- don't think cheap

kartvines · 07-03-2011, 09:41 AM

Quote:

Originally Posted by Ernie Ekberg

JC Whitney has the foil mylar insulation. I can't imagine the mess with plastic bubble wrap. You have a big investment- don't think cheap

Well it is not really bubble warp it is Reflectix, a reflective insulation sheet that has some bubble wrap as the core of two outside reflective sheet , I really don't think that just bubble warp would hold up, but being it is Reflextix it is sold with the claim that 85% of all the heat will be reflected by the outside foil blanket. so it was my thought that is that much heat is reflected off of the wrap only a small ammount will be absorbed into the core. I contact Chief [a member of this group] who did if first and he said so far his has held up with no problem, so I am opinion for the same outcome.

Ernie Ekberg · 07-03-2011, 10:14 AM

Interesting. There are so many new products hitting the market, kinda makes your head swim

Fred and Bonnie · 07-03-2011, 12:22 PM

Anyone give a thought to how the reflective heat will effect engine components?

fred

ga traveler · 07-03-2011, 01:13 PM

Quote:

Originally Posted by Fred and Bonnie

Anyone give a thought to how the reflective heat will effect engine components?

fred

I have always added foil insulation to all my motorhomes. The noise level is reduced by a great amount plus the temp. of the doghouse is a lot less. reflecting the heat just keeps it from absorbing into the MH. I don't see how it would increase the heat in the area.

Cat320 · 07-03-2011, 01:16 PM

I use bubble wrap on the dog house of a diesel boat engine, it works fine and does not get too hot.

Norm3206 · 07-03-2011, 03:38 PM

I used reflectix to line the doghouse in my Itasca with 8.1 L engine. Has been there for 4 years and no trouble. Did cut down on the noise and heat.

kartvines · 07-03-2011, 07:50 PM

I completed my installation today after the caulk dried, I went back with reflective metal duct tape and use it to trim all of the edges to insure they stay in place and also used it on the seams today I went back and added staple and went back and covered all of these area also with the same reflective metal duct tape, I think it turned out just the way I wanted it to and it really seem secure, I don't think it will separate, but then I guess time will tell.
For photos feel free to follow this link:
1983 Fleetwood Pace Arrow Motorhome Restoration Project: Installed a reflective bubble wrap insulation to the underside of my doghouse

Senior Chief · 07-03-2011, 08:03 PM

Quote:

Originally Posted by Fred and Bonnie

Anyone give a thought to how the reflective heat will effect engine components?

fred

Yikes! 400 degrees (direct heat) + 85% of 400 degrees (reflected heat) = 745 degrees !!!! Pull down the Reflectix NOWWWWWW!!!!!!

I'm joking of course. It won't get any hotter than it already is under there unless you interfere with the airflow over the engine

Roger G · 07-04-2011, 06:59 AM

Has anybody done this to the generator compartment? I am thinking about doing this to cut down on noise more so than heat. We use the generator a lot during football season.

Ernie Ekberg · 07-04-2011, 10:01 AM

I suggest the convoluted foam. This will absorb noise instead of having the mylar based foam reflect the noise to the outside.

Possum · 07-04-2011, 10:22 AM

If you have access to a business that does high heat insulation exhaust work (Marine Diesel) you can buy off cuts very inexpensively and attach this to the inside of your doghouse - generator cavity to do both the heat absorption/ reflection and noise absorption and it works great. I got enough to do the dog house and the material thickness is claimed to be 3200° F protection.

The pieces I got I trimmed with a sharp box-cutter and put in place with 3M 90 High Strength Spray adhesive. It has cut back on doghouse heat immensely and I am thinking about covering this heat lining with a heavy grade foil wrap (again using the 3M spray glue) to stop any gunk from sticking to the insulation.

Anyone familiar with the old small block Chevy 400 engine noise will appreciate the great reduction in engine / road noise that also results.