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Topic: Reinsulating the engine compartment (split from Re: What did you do to your coach) (Read 1593 times) previous topic - next topic

Reinsulating the engine compartment (split from Re: What did you do to your coach)

Finished recovering the engine compartment.  The original sound isolating foam insulation was OK, but the covering plastic film had mostly come off and the remaining film was in bad shape.  I got thermal insulation from MOT while we were there ($30/yard, 48" wide).  The insulation they have is not what you would want if you were completely removing the old insulation, since its sound isolating capability is minimal, but for covering the existing foam, it's perfect.  It is a fiberglass reinforced foil surface over 1/2" thick fiber mat - flame retardant (of course), but some sort of felted synthetic.
The stuff is quite hard to cut, but after getting almost completely finished with the engine compartment, I figured out how:
Use single edge razor blades and get a big box of them.  Cut through the reinforced foil with one blade and discard it (it's now too dull after cutting the fiberglass reinforcement).  Use a new blade for cutting the mat.  Cut over a slot in a wood piece if possible.  Replace blades often.  Practice those words... :)) .

To attach, I removed the rest of the old surface film, thoroughly vacuumed the old foam, and then cleaned all the side surfaces several times with alcohol.  Sprayed both the old foam and the mat side of the new insulation with 3M Headliner adhesive.  Attached the mat (sticks really well) and secured it through the old foam with rows of 2" deck screws and fender washers.  Trimmed the edges with 3M aluminum duct tape (the metal foil stuff for high temp, not duct tape).  (The duct tape needs to have a clean surface to stick to, hence the alcohol cleaning.)

I bought 7 yards from MOT (~$210 plus tax) to do both the engine compartment and the generator, and that looks like it will be more than enough.  Much cheaper than replacing all the insulation with new mass-filled vinyl barrier foam, and it should last as long as I do with our rig.  I did practically all the work from inside with the bed raised, but covered engine and bedroom with plastic, which turned out to not be really needed, since there isn't much overspray from the headliner adhesive.

Pictures:
Dave and Nancy
1999/2013 U270 36' Xtreme
Motorcade # 16774
2013 Subaru Outback
KD0NIM

Re: Reinsulating the engine compartment (split from Re: What did you do to your coach)

Reply #1 –
Awesome result Dave! How did you determine that the sound dreading foam was still viable? Did much of it shed during the cleaning process?
Don
Quote from: Dave Katsuki –
Finished recovering the engine compartment. 
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Don & Tys
1999 U270 3602 WTFE #5402
Xtreme Stage 1 w/Headlight, Step Conversion, etc.
2009 Honda Fit Sport with Navi
Freedom is NOT "just another word for nothing left to lose"... with apologies to Kris Kristofferson

Re: Reinsulating the engine compartment (split from Re: What did you do to your coach)

Reply #2 –
No, none of it shed while I was vacuuming it off (but it was really dusty!), and when I picked at the foam to test it, seemed OK, so I went ahead with covering it.  I think even if the original foam isn't so structural any more, it would still be strong enough to hold the surface mat in place, and with the addition of screws and fender washers, it will definitely be fine.  The aluminum tape anchors the edges quite well on ours, but even if the original covering on the edges is coming off, you could still scrape that off and clean the surface enough to stick to the new aluminum foil edging tape.  A tip I forgot on the 2" deck screws -  try to get ones with smooth threads.  If the threads are rough,  the fiber of the mat wraps around the screw, and it takes reversing a bunch of times to get the screw in.
Dave and Nancy
1999/2013 U270 36' Xtreme
Motorcade # 16774
2013 Subaru Outback
KD0NIM

Re: Reinsulating the engine compartment (split from Re: What did you do to your coach)

Reply #3 –
Regarding the 2" deck screws... Did you have some way of setting the depth so they would penetrate enough to grip without going all the way through the wood or were you just eyeballing the depth?
Don
Quote from: Dave Katsuki –
No, none of it shed while I was vacuuming it off (but it was really dusty!), and when I picked at the foam to test it, seemed OK, so I went ahead with covering it.  I think even if the original foam isn't so structural any more, it would still be strong enough to hold the surface mat in place, and with the addition of screws and fender washers, it will definitely be fine.  The aluminum tape anchors the edges quite well on ours, but even if the original covering on the edges is coming off, you could still scrape that off and clean the surface enough to stick to the new aluminum foil edging tape.  A tip I forgot on the 2" deck screws -  try to get ones with smooth threads.  If the threads are rough,  the fiber of the mat wraps around the screw, and it takes reversing a bunch of times to get the screw in.
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Don & Tys
1999 U270 3602 WTFE #5402
Xtreme Stage 1 w/Headlight, Step Conversion, etc.
2009 Honda Fit Sport with Navi
Freedom is NOT "just another word for nothing left to lose"... with apologies to Kris Kristofferson

Re: Reinsulating the engine compartment (split from Re: What did you do to your coach)

Reply #4 –
Just by eyeball, and it's not necessary to go into the wood very far.  I did check the first several under the mattress, but no danger there.  Only going in to the wood 1/2" or so.  If your total depth is less, might need to use shorter screws.
Dave and Nancy
1999/2013 U270 36' Xtreme
Motorcade # 16774
2013 Subaru Outback
KD0NIM

Re: Reinsulating the engine compartment (split from Re: What did you do to your coach)

Reply #5 –
Which components mounted to the insulated walls did you remove versus just cutting around?
Regards,
Brett

'99 42' Foretravel Xtreme
'14 Brown Motorsports Stacker
'05 Chevy SSR
'02 BMW R1150R

Re: Reinsulating the engine compartment (split from Re: What did you do to your coach)

Reply #6 –
Nice upgrade Dave, you must be getting to the top of the curve on Foretravel renovations.  BTW, many thanks for the visors, they saved my peepers driving dead west in the afternoon last month. 

Chuck
"Not so  long ago we were a nation of risk takers, riding five million pounds of  thrust straight into space."  Joe Gresh
Chuck Pearson
1996 U295
2018 Can Am X3 TurboRS

Re: Reinsulating the engine compartment (split from Re: What did you do to your coach)

Reply #7 –
Thanks Dave for the info.
I was just looking at my engine bay insulation today and thinking that what you did is the best way to go - great information on viable products.

Wyatt
96 U320 40 WTFE, build 4943
84 Toyota Supra towd
2015 Jeep Wrangler towd
Victoria, BC, Canada

Re: Reinsulating the engine compartment (split from Re: What did you do to your coach)

Reply #8 –
Quote from: amos.harrison –
Which components mounted to the insulated walls did you remove versus just cutting around?
I removed everything on the side walls except for the air struts (light, fire suppression unit, wires.)  I cheated on the 12V relay/solenoid panel on the back wall, and installed the new insulation in two pieces.  Passenger side installed up to the edge of the panels with edge dressed with tape before gluing down.  For the other side, I removed screws holding the drivers side of the panels down, but just loosened the bolts on the passengers side of the panel,  That was enough to allow me to slip the edge of the other insulation piece under the panels pretty far.  Dressed the edges of the insulation with aluminum tape before pushing them under to make them slide a little easier, but not necessary, I think.  Then tightened bolts and put in new screws on the other side.  Corners taped with aluminum tape.  I think I forgot to say that I installed the drivers side back piece under the relay panels, and then folded it back and sprayed both surfaces with adhesive (suitable masking, etc.)

The tape is pretty nice stuff to work with (I hadn't used it before).  Sticks really solidly to the new insulation and to the old surfaces if you clean them thoroughly with alcohol first.  And if you make a mistake, just cut it back and put a new piece on.  No one will ever know... :))
Dave and Nancy
1999/2013 U270 36' Xtreme
Motorcade # 16774
2013 Subaru Outback
KD0NIM

Re: Reinsulating the engine compartment (split from Re: What did you do to your coach)

Reply #9 –
Dave,. Is the insulation faced on both sides with aluminum ?  Do you see a brand on it ? Maybe I can get it locally instead of having it shipped.
Thanks
Gary B

Re: Reinsulating the engine compartment (split from Re: What did you do to your coach)

Reply #10 –
I don't see a brand on it, and it's faced only on one side.  Maybe J.C. Whipme?  Probably anything to surface the old insulation with an aluminized surface would be a great improvement.  The stuff MOT sells is good because the aluminized surface is backed with a fiberglass scrim, so it's strong.  Would maybe be better if it were backed with fiberglass batting, but then it probably wouldn't stick to the foam.
Dave and Nancy
1999/2013 U270 36' Xtreme
Motorcade # 16774
2013 Subaru Outback
KD0NIM

Re: Reinsulating the engine compartment (split from Re: What did you do to your coach)

Reply #11 –
Dave,

Great looking job and thanks for the specifics on your removal/installation with pictures to boot.

My insulation disintegrates to the touch, is very dirty and falls off in big chunks in both the engine and generator compartments. The old stuff will have to be completely removed and I will probably use the insulation/ sound deadening board as recommended by John Duld American Acoustical Products for Mobile Homes and RVs.  Was this a weekend project or one done over several days?  My old insulation will be a big mess just to remove and a lot of cleaning up after that. I'm not looking foward to it but it is necessary and I hope it turns out as nice as yours did!

Thanks,

Jerry
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Jerry and Cindy Maddux
1993 U300/36WTBI DD6v92TA
build 4271  "Miss Lou"
1995 suzuki sidekick 4x4 toad
Gulfport, Ms

"Pride of Ownership"

Re: Reinsulating the engine compartment (split from Re: What did you do to your coach)

Reply #12 –
Question:
Would adding the reflective insulation as Dave has done keep the original sound deadening material from deteriorating further?  Or will it all need to be replaced at some point regardless of being covered up?
Bill & Jan Velting
1998 U320 36'    2014 Xtreme facelift
build #5339  MC#17207
current toad: 2014 Cadillac SRX

Re: Reinsulating the engine compartment (split from Re: What did you do to your coach)

Reply #13 –
Bill,

IMHO, the deterioration (i.e., aging) will continue.  A major factor in the aging process is the effect of high temperature, which isn't going to change.  My leaded foam insulation crumbled into sand-like particles after about 17 years.
Don Hay
'92 Grandvilla, U-280
The Hayfever Express
Build #4055
'97 GEO Tracker
Life is like licking honey off a thorn.

Re: Reinsulating the engine compartment (split from Re: What did you do to your coach)

Reply #14 –
Quote from: coastprt –
...
Was this a weekend project or one done over several days?  My old insulation will be a big mess just to remove and a lot of cleaning up after that. I'm not looking foward to it but it is necessary and I hope it turns out as nice as yours did!

Thanks,

Jerry

My project was done over several days, mainly because I wanted to avoid really windy weather (didn't want to chase the insulation or spray adhesive into the bedroom), but I estimate that it would take about 6-8 hours if you were pushing hard and had all the materials at hand.  Not sure how long the foam will last under the new insulation, but at least it will be captured...

If my old insulation was falling off, I would certainly have done complete removal and replacement with new mass-loaded foam.

Hope I don't have to go that route for a long time.
Dave and Nancy
1999/2013 U270 36' Xtreme
Motorcade # 16774
2013 Subaru Outback
KD0NIM

Re: Reinsulating the engine compartment (split from Re: What did you do to your coach)

Reply #15 –
Here is a source for thermal/accoustical insulating products.  Some are rated to 1500 degrees.  Amazon carries part of the product line, looks like about 2.00 a sq. ft.

Thermo-Tec : Products by category

Chuck
"Not so  long ago we were a nation of risk takers, riding five million pounds of  thrust straight into space."  Joe Gresh
Chuck Pearson
1996 U295
2018 Can Am X3 TurboRS

Re: Reinsulating the engine compartment (split from Re: What did you do to your coach)

Reply #16 –
This is on my to-do list, as well as insulating the turbo. Is the 15002 what I need for my 6V92 Detroit, or is it more for cars?
 

Re: Reinsulating the engine compartment (split from Re: What did you do to your coach)

Reply #17 –
Quote from: Chuck Pearson –
Here is a source for thermal/accoustical insulating products.  Some are rated to 1500 degrees.  Amazon carries part of the product line, looks like about 2.00 a sq. ft.

Thermo-Tec : Products by category

Chuck

Thanks for the link!  This one: Thermo-Tec Automotive - 48" x 72" 1-SIDED THERMO  looks like what MOT is selling.
Dave and Nancy
1999/2013 U270 36' Xtreme
Motorcade # 16774
2013 Subaru Outback
KD0NIM