So last week I hit my head again on the forward Robust CRT TV box. At that moment I impulsively pulled the box out to cut down. It's 25 inches wide so in my opinion is too small to adequately fit a 32" TV and I'm currently have my reserves on using a 24". But I do know I'll never hit my head on it again. I'm pushing the face of it back 5" and reducing the height to 14" that it will and down. I'll get dome doors made on the inside so I'm not looking at a black hole and basically get it out of head banging distance. Thinking I'll a magnetic mount to put a 32" tv on and store in the closet while underway or have a second mount else where in the coach. If I watch using the smart tv functions I currently don't need to see. Would also allow using outside if there is a mount for it there and could be.
This was were the problem really showed it's undisclosed problems. I knew all my insulation was failing everywhere else and had always assumed it would be as it it. A HUGE MESS. I pulled out all I could by hand and will wire brush by hand and vacuum to remove the rest. The clearance lights are covered with white RTV and future upgrading to LEDs should also be completed before before reinsulating. I will be using orange spray foam as I have on many projects in the past. It is also rated as a adhesive and is a approved fireblock material. I will stack 1 1/2" beads till it is covered.
https://www.lowes.com/pd/Dow-Great-Stuff-Pro-GREAT-STUFF-PRO-Gaps-and-Cracks-24-oz-Spray-Foam-Insulation/3378594
Bigger beads can be made but tend to sag before they cure. Minimal offgassing during curing and none after curing is compleated .
2 Pack Pu Expanding Caulking Gun Aluminum Caulking Foam Gun Foam Sprayer PU... (https://www.amazon.com/gp/product/B07Z2464XX/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1)
Requires using a gun.
Can also use Tygon tubing to extend into tight areas.
What a mess
Scott
Getting rid of that insulation will save quite a bit of weight. I used some old dishwasher insulation, some sheet urethane insulation
and some reflective bubble wrap insulation. Very crude but affective as not problem last winter at below 0 F. If you got rid of the
left hand cupboard you could put up a 40 inch TV or bigger. Getting rid of the head banger is great.
Yes it's quite heavy. May bond a finish layer of foil double bubble on inside for looks. Just don't watch tv that much, would actually consider a curb side retractable if going big. Figure that out down the road in a few years
Scott
So tonight I got back up in the compartment with a wire brush and the vacuum. Cleaned down to the bare fiberglass and vacuumed all the old mess out of there. I had a little over one can of foam at the house and the gun was not dried up so I started building up my new insulation. One can builds about three inches tall so I'll pick up five more cans. I have a window to install in a rental house in the near future so having some left over is okay. Full cans can and should be returned.
https://www.lowes.com/pd/Dow-Great-Stuff-Pro-GREAT-STUFF-PRO-Gaps-and-Cracks-24-oz-Spray-Foam-Insulation/3378594
They do eventually time out. Built up about a 3"x3" base to build up with. Will only do one layer every eight hours or so. Building up this thick has a tendency to sag. Couple days it will be ready for final layer inside of double bubble foil insulation. This stuff is messy. A can of brake cleaner is your friend. Used about eight inches of Tygon tubing tied to the gun nozzle. Quite difficult to reach ends and poor placement control.
Scott
I don't watch TV either, but if I did I would have a 55" or bigger one mounted on the side of the coach with suction cups. Take it down and stow it in a compartment when not in use.
The weight (density) of the original insulation is a major contributor to its sound absorbing qualities.
Unfortunately you are correct. Shredded denim is real hi on the sound absorption scale. I've used the hand applied foam with good results. Possibly the imperfections, irregularities improve this. It will deaden the fiberglass and insulate adequately for me. Been around turbine jets for many years, so a lot of the noise has already had the top clipped off for me already. Anything to help keep it cool works for me.
Scott
Half way done with spray foam. Probably ends up being about pound and a half foam
Scott
Saga continues. Got a good Bored retired boss of mine that is a top finish carpenter. I marked CRT forward box and handed it to him. Week later he handed it back completed. Shoved it back in the hole to mock up and so for I'm quite please in the fact I'll possibly never bang my head on that thing. Down to possibly the last of the foam beads to place. Will address covering int up later. Had to plug the hole then red rolled another hole for the lower light. Not perfect, but in my coach no one will ever notice.
Scott
How many cans of foam to complete the insulation?
So I started about four inches thick at bottom and tapered down to a single row at top. 7 x $15 a can and two cans of brake clean for clean up
Scott
I would not use spray foam. Here's why. When having my coach painted in Mexico the painter cut my new LED clearance light wires. I couldn't believe he did that they were brand new. And he cut it really close to the fixture. I had to splice new wires in for several of them. I would not have been able to do that with spray foam without digging it all out. Well I guess you could have put a screwdriver through the hole and just removed around there but I needed access to the wiring behind it too.
What I did was to put the sound deadener that they sell for Auto stereo installations to minimize harmonic vibrations on first. After that I used 1/2 inch thick maybe or 3/4 inch insulation with a reflective foil. That also is self-adhesive and I covered all the seams with metal tape. It was a lot easier to get to the wires to replace when I needed to for that snafu. It does a really good job of cutting the heat load and the sound down. The insulation at four travel used is deteriorating everywhere on our coach seen or unseen. And it is a mess to clean up. The whole front cap in is covered in it and behind the dashboard. Impossible get to. Maybe spraying foam there would be a good choice but it would mix with the wiring and make it difficult to access things like the windshield washer nozzles that I have to replace this week. When I took out the foam under the bed, that was a real mess. Still haven't finished insulating with the sound down that I bought. One more piece to go.
Everything subcomes to time eventually.
Yes there are many different types of foam. I've personally had outstanding results using different foam products. I actually own two foam cutting tables and literally have cut 20K pounds of foam working with my brother. You are 100% correct in burying any thing with any product, don't do it if possible. All of my wiring is exposed and loose for future work. Yes the foam product must be matched to what you are doing. Flammablity and outgassing should be hi on the concerns. It will outlive the life of the coach. IMO
Scott
What thickness are you using?
Thanks,
Trent
Some spray on foam products generate enough heat while they are curing to damage PEX tubing. Use with caution.
Roger I think those would be catalyzed two component. I've never noticed a temperature increase with this product. Googled and found the following
(200°F.
For all PEX pipe and tubing, the maximum operating temperature is 200°F. No PEX should be operated at temperatures above 200°F for any length of time. The use of crosslinked polyethylene (PEX) pipe and tubing in high- temperature applications with operating temperatures above 180°F may affect the tubing's design life.)
I better plan on moving out of the desert, I swear it gets that hot here. My solar collectors run at 200 deg. For the house. Kitec tubing. Well beyond it's recommended range.
Scott
Reinstalled cut down CRT box and will cover over for now. So much extra room. Didn't hit my head once today. Mounted quad camera below it. Still need to clean 20 years of stains of the tan Naugahyde. And will also eventually address the cream colored headliner, but not today. Real happy getting that monster down to a manageable size.
Scott