engine compartment insulation revisited

Topic: engine compartment insulation revisited (Read 2646 times) previous topic - next topic

Re: engine compartment insulation revisited

Reply #25 – May 11, 2011, 10:46:57 pm

While I am still gathering all the information on 5 brands of insulation (still waiting to hear back from one company). Here are some things I found out: First, most sound absorbing foam is given a Sound Transmission Class number- the higher the number the better. Two, all but one of the foam based products meet the Federal Motor Vehicle Safety Standard 302 and even the one that does not says that their insulation is made for engine compartments, just don't put it right next to a turbo or exhaust pipe. Three, all of them have a metalized plastic cover over the foam. (If mine did it was not there when I bought the coach.) Four, the prices vary widely but the most expensive is not necessarily the best.

I am in the process of removing the insulation and am taking pictures but I cannot really show a before since much of the insulation has already fallen off. I can tell you that whatever they used for glue still works!

Re: engine compartment insulation revisited

Reply #26 – May 13, 2011, 10:08:09 pm

I heard back from the last company and I can now present my findings. I've attached a Microsoft Office 2003 version of Excel worksheet showing the five companies that I used. The original foam in my coach, I believe, was Barymat BUF24C, which is no longer made. The replacement is BTMM-14C, according to my notes from 2009 when I first looked into this. Two of the products have an adhesive backing, Technicon and E.A.R. The Technicon product supplied by West Marine includes seam tape and a hanger kit.

I will be ordering the Barymat foam next week. I based my decision on the fact that it has the highest STC of any of them and one of the lowest prices. I am taking pictures as I go and will post those along with the cost for the seam tape and whatever adhesive they recommend.

Re: engine compartment insulation revisited

Reply #27 – May 18, 2011, 11:53:04 am

Thank you John for sharing this. Karma to you.

Re: engine compartment insulation revisited

Reply #28 – May 18, 2011, 08:37:46 pm

While we were at FOT in February this year I meet an owner named Steve (unfortunately I don't remember his last name) who had redone the engine compartment and generator compartment with a product from Menards that had foil on both sides with foam insulation inthe middle. It was a rigid board that he put right over the existing insulation and fastened it with deck screws, fender washers and aluminum foil along the edges. Steve said it worked great. He also wanted to see Kent Speers as he had the same year and model FT. But Kent left before they had a chance to meet--I think.
Any input on this product application??

Re: engine compartment insulation revisited

Reply #29 – May 19, 2011, 02:58:55 pm

Just checked Menard's. Don't know whether it was just regular insulation or the sound control insulation. In any case, neither product is designed to be used in motor vehicles. All the ones I have listed are specifically designed for engine compartments. Who knows what will happen to the Menard's insulation if it comes into contact with oil, antifreeze or diesel fuel. The Menard's insulation is probably as fire resistant but to a different set of codes.

Re: engine compartment insulation revisited

Reply #30 – May 19, 2011, 11:32:35 pm

I finally came across what I used to protect the foam from the exhaust brake I installed that I felt was too close for comfort. In my case the brake and exhaust tubing was within three inches of the foam. I used sheet metal screws to attach it to the plywood through the foam. Here's the web site:

Reflective Heat Shield-Competition Products

Re: engine compartment insulation revisited

Reply #31 – May 25, 2011, 09:26:29 pm

I was looking at my engine compartment and wondering how to go about fastening to the ceiling area on either side of the underside of the bed. All my plastic is gone and the foam in some spots comes off in particles with just a touch. I can't really see the surfaces between the CAC and the radiator to see if this particulate is coating them but I wouldn't be surprised and this doesn't look like an easy area to access either.

Re: engine compartment insulation revisited

Reply #32 – May 25, 2011, 09:51:07 pm

Dwayne,

I can't tell you how to fasten new insulation to the underside of the bed, but I can offers some suggestions for removing the disintegrated insulation. I've had good luck in using various sizes of clear flexible plastic tubing as a vacuum cleaner hose. I used duct tape to attach the clear tubing to the end of the cone shaped attachment that came with my Craftsman vac. And I used a long wood dowel taped to the clear tubing to push it into hard to reach crevices. Worked great for me. However, I have not used this technique on my engine as my insulation is still intact. Or, you might be able to use an air hose to just blow it out of the way, as long as it doesn't get blown into something that could create problems. In that regard, I'm in over my head here.

Re: engine compartment insulation revisited

Reply #33 – May 25, 2011, 10:00:48 pm

Dwayne,

Is your unit one with a side radiator? The access on the radiator side is terrible. In addition to the adhesive mine had plastic washers and square drive screws in the "roof" under the side of the bed. I used a plastic scraper to get off most of the insulation and then used a square drive bit in a magnetic socket attached to a ratchet to get the screws out. All of the screws could be barely reached from the side access door. The hard part is getting off the glue that the foam was attached with. The area is too tight to get any powered tools in there, I had to use a spray can of Goof Off. I sprayed a small area because the Goof Off goes away quickly and then scraped it with a carbide paint scraper. Warning! If you do this wear long sleeves and put a tarp under the engine bay. When you do the rear you will need an additional tarp to cover the bumper. The other problem area in mine is the front vertical "walls" in those side compartments. The one in front of the radiator is even tighter that the "roof". I washed down those walls with acetone . Acetone does soften the fiberglass but if you let it dry without touching it with any tools then it will get hard again. Attached is the photo of the area I'm talking about.

Since another post occurred while I was writing this one I need to respond to it also. In my case the insulation in the engine compartment cannot be removed with a vacuum cleaner as it is a three part insulation and the center part is a very heavy vinyl. Only the outer layer could be removed by that means and you would still have to scrape or tear the other off. i would say that the insulation just under the bed weighed about forty pounds.

Re: engine compartment insulation revisited

Reply #34 – May 26, 2011, 10:28:16 am

Mine is the side mounted one and looks like yours. I'm not sure I'm ready to tackle it just yet. The idea of just covering up what's there seems better than trying to remove it all. Working above that radiator or the ceiling aside the hatch/bed will not be much fun.

Re: engine compartment insulation revisited

Reply #35 – May 26, 2011, 12:06:13 pm

I'm going to go with a foil based recover of existing insulation once I locate a suitable material. The existing insulation is high dollar stuff,very effective in sound dampening, well installed, hard to remove as it's glued, screwed and tattooed. The surface of the existing insulation can be stabilized with a spray adhesive before the new outer liner is installed.

Chuck

Re: engine compartment insulation revisited

Reply #36 – May 26, 2011, 02:17:15 pm

I think I'll opt for your solution. Please update all of us after you get 'er done. If all goes well I'll buy the same stuff and you can give pointers on what is certain to be a tough job even just covering what's there.

Screws and washers for engine bay insulation

Reply #37 – May 29, 2011, 11:57:03 pm

My '91 GV had rusting 1-1/4" square drive screws and 1-1/2" plastic washers painted black holding up the insulation. I wanted to replace the screws with stainless steel and the washers with either aluminum or stainless steel. It turns out that finding washer head stainless square drive screws is not easy. McFeely's carries Kreg pocket hole washer head stainless steel screws in two configurations:
fine thread, #7 X 1-1/4" Kreg Pocket Hole Screws - 305 Stainless Steel, Screws, Fasteners -
and coarse thread, #8 X 1-1/4" Kreg Pocket Hole Screws - 305 Stainless Steel, Screws, Fasteners -

The screws that came out were 14 threads per inch while the coarse thread screws are only 8 threads per inch. I was concerned that the coarse thread screws would not hold up as there would be very few threads in the plywood and fiberglass so I devised a test. I screwed three different screws (pocket hole coarse thread, the original screw and a sheet metal screw) about 3/8" into the wood which duplicated the depth of the original screws. I then fastened a weight to the screw. I started with the coarse thread screw and slowly added weight. I gave up at 10 lbs. and stopped my testing as it seemed that any one of them would hold up the insulation.

The original washers were about .060" nylon with a 1/4" i.d. and a 1-1/2" o.d. and said "Handy". I could not find any washers in that o.d. that had a 1/4" i.d. so I ended up making my washers out of .060" aluminum. I used a 1-1/2" hole saw to cut the strips of used aluminum sheet that I sheared using a friend's shear. The hole saw leaves a burr on the washer that required me to wire brush each one. I then put them in a tumbler to clean and polish them.

Here is a photo of the washer cutting set up.

Re: engine compartment insulation revisited

Reply #38 – May 30, 2011, 07:53:41 am

I am continually impressed at the level of creativity and knowledge of so many Forum members. Very nice work, John.

Re: engine compartment insulation revisited

Reply #39 – May 30, 2011, 08:33:34 am

John, Pretty neat and creative.
An observation, How about using 1 1/2 or 2 inch wide aluminum sheet and cutting it into squares ? I don't see any real reason that washers would have to be round.

Re: engine compartment insulation revisited

Reply #40 – May 30, 2011, 09:01:30 am

The points on the squares will tear the insulation and rapidly degrade the installation.

Re: engine compartment insulation revisited

Reply #41 – May 30, 2011, 09:04:58 am

OK, Thought there might be a reason for round washers.
On an 85 ORED that I had I used 2' wide wood strips with screws to hold the insulation up under the bed.

Re: engine compartment insulation revisited

Reply #42 – May 30, 2011, 10:11:48 am

Gary,

I am afraid I am of the school of "keep it original as possible". I did that with my Toyota race car ordering the correct bolts for a location so that all the heads would used the same socket. I could have purchased 1-1/4" stainless steel washers for about $10 plus shipping and done a lot less work. I wasn't sure that the somewhat smaller washers would have enough surface area to not punch through, hence all my work. I am also using square drive screws instead of phillips for the same reason.

Re: engine compartment insulation revisited

Reply #43 – May 30, 2011, 11:00:07 am

Have used "Fender Washers", they are available in different sizes, most are plated steel, not galvanized. Cheap and available at most electrical supply houses .

Re: engine compartment insulation revisited

Reply #44 – June 11, 2011, 11:33:11 am

Big thanks to John Cooper.

Your spreadsheet saved me a lot of time.

The long and the short of all the products mentioned here, and from dozens of google links I checked on the subject of insulating the engine and generator bays, is: the heat ratings. Almost all of the products I looked at have a relatively low heat rating. Most are more about acoustic insulation rather than heat insulation.

The exception to this are products from HeatShield Products. The HP Heatshield mat (in the Marine section) is rated to 1100 degrees F continuous, 1800 intermittent, and 450 direct --> HP Heatshield Mat | Heatshield Products . A clear winner with regards to heat insulation. Meets Coast Guard standards for non-flammability. Part number 721505 is a 58 inch by 60 inch self adhesive roll. Best price I've found thus far is $105 less shipping.

This is the stuff I'm going to use to line my gen bay and engine bay, adding some under the bed to supplement what's already there. For the front firewall area I can use a less expensive low temp material. The HP Heatshield mat is only 0.040 inches thick, so it doesn't provide any sound deadening. At the same time that 5X5 roll weighs only 3 lbs, so overhead applications would not need supplemental fastening. I think if you're looking for sound insulation as well, you would need to add dynamat or a similar alternative underneath. Still considering that.

Steve

Re: engine compartment insulation revisited

Reply #45 – June 11, 2011, 01:43:06 pm

I was at Xtreme Paint and Graphics last week and saw a tech putting new insulation in the generator bay for James Stallings' Prevost. It looked the "egg crate" foam used for sound insulation and for some mattress toppers. They said it is rated for engine compartments. They get it from an outfit in East Texas that builds refrigeration units for trailers.

If I were relining an engine compartment, I would check with Stallings regarding the material he is using for his coach.

Re: engine compartment insulation revisited

Reply #46 – June 12, 2011, 07:56:15 am

I've seen that kind of material in my quest. What I did come across did not have a high temp rating. I think that even if it did, over time it would get pretty dirty and might be a task to clean. The foil faced stuff might hold up a little better. Don't know.

I'm more interested in heat containment than noise abatement, although that factors in as well. At this point, the tentative plan is to use a product called "edead" as an underlayer for noise abatement (Elemental Designs: Car Stereo, Home Speakers, Electronics ), and the HP Heatshield mat over top as a heat shield and fire retardant. Found a lot of very positive reviews for the edead product on a number of forums.

Something that may help in understanding the different offerings out there --> Welcome to Sound Deadener Showdown | Sound Deadener Showdown

Stay away from asphalt based products - like the orginal dynamat and a few others out there. At higher temps the adhesive fails and it will start melting. I've seen a number of people state they used Lowe's Peel & Seal as a sound deadener - this is asphalt based, and does not have a strong enough adhesive for overhead use.

Comes down the right material for the job, and it seems that here, as with most things, you get what you pay for.

The quest continues.
Steve

Affiliate Notice