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[GMCnet] Foam removal - PITA - Do I do things wrong [message #283916] Tue, 04 August 2015 10:16 Go to next message
Olly Schmidt is currently offline  Olly Schmidt   United States
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Morning,

I am removing the insulation from the ceiling today. It took me 30
minutes to clean a little rectangle.

Is there a faster / easier way of doing this kind of removal.

Tools and results can be seen at

http://www.gmcmhphotos.com/photos/foam-removal/p58831-dsc-3208.html

Any and all hints are greatly appreciated.
--
Best regards

Peer Oliver Schmidt
PGP Key ID: 0x83E1C2EA

'76a Eleganza II, VA

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Olly Schmidt
PGP Key ID: 0x18a9 3a1f 4196 bf22
'76a Eleganza II, VA
'73 Sequoia, SH, Germany
Re: [GMCnet] Foam removal - PITA - Do I do things wrong [message #283921 is a reply to message #283916] Tue, 04 August 2015 10:51 Go to previous messageGo to next message
77Royale   United States
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I used one of these on my cordless drill.
http://www.homedepot.com/p/3M-Pro-Grade-4-in-Coarse-Paint-and-Rust-Stripper-7771-PG/202940537

I also wore a dust mask with a filter, and duct taped my shop vac to the end of the drill with the crevice attachment on the hose. So when the drill was moving 95% of the little particles were sucked right into the shop vac. Done. Overall very little mess to clean up.

That course wheel will shave off the foam pretty much instantly and you will still have some control to not go too far. But it looks like your removing it all the way. I indicated in another post that I only smoothed out the high spots in the spray foam. Enough to slip a 1/2 inch Rmax board into place and make it all uniform for the FRP to snug up against it.

Some benefits, That wheel will not chew through buried wires instantly, giving you some time to stop the drill. The foam does not readily stick to the wheel and can be vacuumed/knocked clean. 8 bucks, and some strong arms for the overhead work was all it took.


77 Royale, Rear Dry Bath. 403, 3.55 Final Drive, Lenzi goodies, Patterson carb and dizzy. Mid Michigan
Re: [GMCnet] Foam removal - PITA - Do I do things wrong [message #283926 is a reply to message #283916] Tue, 04 August 2015 11:19 Go to previous messageGo to next message
werewilfs is currently offline  werewilfs   United States
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I believe those who have done this have purchased the "GMC Tool" at Harbor Freight which makes quick work of the insulation.

I think this is the one...

http://www.harborfreight.com/power-tools/oscillating-tools/oscillating-multifunction-power-tool-62279.html

A new Harbor Freight just opened in Culpeper, VA this weekend. About 90 miles or so away from you... Perhaps you can stop there on your way to visit is up in Rockville this weekend for the All GM show. Wink


Jared & Stefanie Kohl Rappahannock County, VA 1973 Painted Desert "Onslow"
Re: [GMCnet] Foam removal - PITA - Do I do things wrong [message #283933 is a reply to message #283926] Tue, 04 August 2015 11:41 Go to previous messageGo to next message
A Hamilto is currently offline  A Hamilto   United States
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werewilfs wrote on Tue, 04 August 2015 11:19
I believe those who have done this have purchased the "GMC Tool" at Harbor Freight which makes quick work of the insulation.

I think this is the one...

http://www.harborfreight.com/power-tools/oscillating-tools/oscillating-multifunction-power-tool-62279.html

A new Harbor Freight just opened in Culpeper, VA this weekend. About 90 miles or so away from you... Perhaps you can stop there on your way to visit is up in Rockville this weekend for the All GM show. Wink
That make/model of oscillating saw may or may not last through the entire job, but is worth a try.

Peer,

What you want to do is leave 3/4" to an inch of the original insulation and add 3/4" or 1/2" polyisocyanurate sheeting to get insulation flush with the ribs.

If you are not going to spray foam the cavity, you want to leave the old stuff because it is semi-structural (stiffens the roof).

To answer your question, it takes time and effort to remove that stuff completely. That is another reason I said to not remove all of it.
Re: [GMCnet] Foam removal - PITA - Do I do things wrong [message #283934 is a reply to message #283933] Tue, 04 August 2015 11:44 Go to previous messageGo to next message
A Hamilto is currently offline  A Hamilto   United States
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A Hamilto wrote on Tue, 04 August 2015 11:41
werewilfs wrote on Tue, 04 August 2015 11:19
I believe those who have done this have purchased the "GMC Tool" at Harbor Freight which makes quick work of the insulation.

I think this is the one...

http://www.harborfreight.com/power-tools/oscillating-tools/oscillating-multifunction-power-tool-62279.html

A new Harbor Freight just opened in Culpeper, VA this weekend. About 90 miles or so away from you... Perhaps you can stop there on your way to visit is up in Rockville this weekend for the All GM show. Wink
That make/model of oscillating saw may or may not last through the entire job, but is worth a try.

Peer,

What you want to do is leave 3/4" to an inch of the original insulation and add 3/4" or 1/2" polyisocyanurate sheeting to get insulation flush with the ribs.

If you are not going to spray foam the cavity, you want to leave the old stuff because it is semi-structural (stiffens the roof).

To answer your question, it takes time and effort to remove that stuff completely. That is another reason I said to not remove all of it.
Here's what Wally used:

http://www.gmcmhphotos.com/photos/power-level-valve-fitting/p29855-insulation-trimmer.html
Re: [GMCnet] Foam removal - PITA - Do I do things wrong [message #283935 is a reply to message #283934] Tue, 04 August 2015 11:49 Go to previous messageGo to next message
Olly Schmidt is currently offline  Olly Schmidt   United States
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It was way easier to remove down to the metal, than to just get rid of a
bit. I'll meditate on the oscillating thingie Jared posted, but will
probably not drive a total of 200mls just to get it

--
Best regards

Peer Oliver Schmidt
the internet company
PGP Key ID: 0x83E1C2EA


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Olly Schmidt
PGP Key ID: 0x18a9 3a1f 4196 bf22
'76a Eleganza II, VA
'73 Sequoia, SH, Germany
Re: [GMCnet] Foam removal - PITA - Do I do things wrong [message #283938 is a reply to message #283933] Tue, 04 August 2015 11:58 Go to previous messageGo to next message
Jp Benson is currently offline  Jp Benson   United States
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Wow that looks nice and clean. Only about 15 more hours to finish the ceiling. I did the partial removal and added 1/2" or 3/4" RMax as needed. The HF multi-function tool worked for me but I did have to repair it once. The circular blade (with the kerf ground off the teeth - less dust) worked best and gave the most control. Great Stuff did a nice job of bonding the RMax to the old foam.

JP
Re: [GMCnet] Foam removal - PITA - Do I do things wrong [message #283941 is a reply to message #283938] Tue, 04 August 2015 12:28 Go to previous messageGo to next message
A Hamilto is currently offline  A Hamilto   United States
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Jp Benson wrote on Tue, 04 August 2015 11:58
Wow that looks nice and clean. Only about 15 more hours to finish the ceiling. I did the partial removal and added 1/2" or 3/4" RMax as needed. The HF multi-function tool worked for me but I did have to repair it once. The circular blade (with the kerf ground off the teeth - less dust) worked best and gave the most control. Great Stuff did a nice job of bonding the RMax to the old foam.

JP
Peer,

Heed what JP just said.

You don't need to drive 200 miles to pay $20 for an oscillating tool, you can get one from a nearby big box store for $70 and up for cordless and $100 for corded. For the amount of time it is going to be running, you want corded.

If it is going to take 20 hours to do it by hand, or 8 to use a power tool, you can decide if you want to spend the money.

And remember:

1. The spray foam that is there adds rigidity to the roof, removing it reduces that rigidity.
2. The rigid sheets cost about $10 more per half inch of thickness that you buy. I.E., if you buy half inch thick sheets they are around $10 each, one inch is about $20 per sheet and two layers of 3/4" will be about $30. Every half inch you remove is another $50 in material you have to buy for the project to replace it. If you put half an inch on the whole ceiling, it will cost around $50 for 5 sheets. 3/4" would be about $75 for 5 sheets. An inch for the whole ceiling will run $100 for 5 sheets. An inch and a half will cost about $150 for 10 sheets of 3/4".

Do what brings you the most joy.
Re: [GMCnet] Foam removal - PITA - Do I do things wrong [message #283943 is a reply to message #283941] Tue, 04 August 2015 12:44 Go to previous messageGo to next message
appie is currently offline  appie   Netherlands
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Used a old chissel, worked fine

Appie eleganza 76 "Olga" now sadly sold 6 wheel discbrake Quadrabags Springfield stage 2 462 olds Manny tranny ( pictures at http://www.gmcmhphotos.com/photos/g6489-olga.html Fulltiming in Europe july 2014 til july 2016 Denmark
Re: [GMCnet] Foam removal - PITA - Do I do things wrong [message #283944 is a reply to message #283941] Tue, 04 August 2015 13:34 Go to previous messageGo to next message
Olly Schmidt is currently offline  Olly Schmidt   United States
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I chose the locally sourced (corded) power tool. It is definitely
messier :) and more fun :)).

Not sure I used the correct front. I used what looks to be a saw type
thingie. The one on the lift of this picture:

http://images.lowes.com/product/converted/845534/845534054910.jpg

I chose the complete removal, as I will be way too un-handy with these
tools to provide a smooth surface.

--
Best regards

Peer Oliver Schmidt
the internet company
PGP Key ID: 0x83E1C2EA


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Olly Schmidt
PGP Key ID: 0x18a9 3a1f 4196 bf22
'76a Eleganza II, VA
'73 Sequoia, SH, Germany
Re: [GMCnet] Foam removal - PITA - Do I do things wrong [message #283945 is a reply to message #283944] Tue, 04 August 2015 14:08 Go to previous messageGo to next message
A Hamilto is currently offline  A Hamilto   United States
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Peer Oliver Schmidt wrote on Tue, 04 August 2015 13:34
...I used what looks to be a saw type thingie. The one on the lift of this picture:
http://images.lowes.com/product/converted/845534/845534054910.jpg

I chose the complete removal, as I will be way too un-handy with these tools to provide a smooth surface. ...
The surface doesn't have to be smooth, you can fill in thin spots with canned spray foam.

If you persist in complete removal, be careful not to scratch up the aluminum roof. Then I suggest two layers of 3/4" foil faced polyisocyanurate. They will conform to the roof curve easier and the extra layers of foil reflect heat both ways (in and out). Keeps more heat out in Summer and more heat in during Winter. If you stick it to the roof with spray foam, it will restore some of the rigidity.

Pay attention to the R-value of the foam board you buy. Foil faced polyisocyanurate has an R-value of about 7 per inch of thickness, that would give you better than R-10 in an inch and a half. Some rigid foam insulation has an R-value lower than 5 per inch, the best you could get in an inch and a half of that would be 7 or so. 30% less R-value in the same thickness.
Re: [GMCnet] Foam removal - PITA - Do I do things wrong [message #283947 is a reply to message #283945] Tue, 04 August 2015 15:04 Go to previous messageGo to next message
Olly Schmidt is currently offline  Olly Schmidt   United States
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I can't seem to find anything better than R4 or R5 locally.

And I might have found the way that works best for me. The middle
rectangle with the fan took 20 minutes. This was using a combination of
brute force with the hammer pictured in my first photo, and the
oscillating thingie I bought. Still dirty as heck, but I'll get at least
the first 4x8 section cleaned today. Still have 8 hours left after all,
and am more than halfway done :D

--
Best regards

Peer Oliver Schmidt
the internet company
PGP Key ID: 0x83E1C2EA


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Olly Schmidt
PGP Key ID: 0x18a9 3a1f 4196 bf22
'76a Eleganza II, VA
'73 Sequoia, SH, Germany
Re: [GMCnet] Foam removal - PITA - Do I do things wrong [message #283949 is a reply to message #283944] Tue, 04 August 2015 15:19 Go to previous messageGo to next message
Jim Miller is currently offline  Jim Miller   United States
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Peer,

I disagree with the admonitions to try and leave in part of the old foam and “just shave it” enough to fit another board on top - with gaps filled in by some sort of messy and sticky spray foam. Going direct to metal not only will take LESS time than the “shave” method but also will let you achieve complete coverage with uniform thickness of insulation. If the new boards are cut properly then you will need no adhesives - only foil tape as shown in my gallery. The trick is to cut the new board to size, use a utility knife to slice down the center of it so as to form a hinge out of the foil on one side - then break the board (while keeping the “hinge” intact) and then fold it up into place between the ceiling rails so that the ends of the board wedge snugly against the rails. Do the same for the board underneath it and then heal the cut part of the hinge with foil tape. Using two boards of the proper thickness will perfectly fill the gap and the boards will be captive above the lips of the rails.

Using the oscillating “GMC TOOL” set at the proper speed and with the proper blade (2.5cm wide with saw teeth on the end) will let you remove the old foam and go completely to the metal in very short order once you develop the technique. Look at picture #6 in the gallery to see how I’ve started a small area from which I will then work outward. Start in that area and use the blade of the GMC tool to slice in between the metal and the foam - you can plunge the entire depth of the blade - then move over a blade width and plunge again - and once you’ve done this all the way around the starting opening you can use the springiness of the blade to pop out significant pieces of foam all at once.

You’ve seen my photo gallery and how cleanly the old foam can be removed using this method. What you saw in those pictures took only a couple evenings of effort and was easy to clean up since the old foam was mostly removed in large chunks rather than as dust or shavings.

http://www.jcmco.com/gallery/album01

--Jim "saving the lives of Onans...one unit at a time" Miller
1977 Eleganza II
1977 Royale
Hamilton, OH


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Re: [GMCnet] Foam removal - PITA - Do I do things wrong [message #283951 is a reply to message #283947] Tue, 04 August 2015 15:58 Go to previous messageGo to next message
A Hamilto is currently offline  A Hamilto   United States
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Peer Oliver Schmidt wrote on Tue, 04 August 2015 15:04
I can't seem to find anything better than R4 or R5 locally. ...
If its pink, it is probably expanded polystyrene or EPS. EPS will absorb water. polyisocyanurate will not. Avoid EPS if you can.

Where are you in VA? I will surf the interweb and find the nearest source of rigid foil faced poly.
Re: [GMCnet] Foam removal - PITA - Do I do things wrong [message #283952 is a reply to message #283951] Tue, 04 August 2015 16:12 Go to previous messageGo to next message
Olly Schmidt is currently offline  Olly Schmidt   United States
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> Peer Oliver Schmidt wrote on Tue, 04 August 2015 15:04
>> I can't seem to find anything better than R4 or R5 locally. ...
> If its pink, it is probably expanded polystyrene or EPS. EPS will absorb water. polyisocyanurate will not. Avoid EPS if you can.
>
> Where are you in VA? I will surf the interweb and find the nearest source of rigid foil faced poly.
I am in Farmville, seems to the center of nothing...

I gladly accept your offer for finding something for me. :)

--
Best regards

Peer Oliver Schmidt
the internet company
PGP Key ID: 0x83E1C2EA


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Olly Schmidt
PGP Key ID: 0x18a9 3a1f 4196 bf22
'76a Eleganza II, VA
'73 Sequoia, SH, Germany
Re: [GMCnet] Foam removal - PITA - Do I do things wrong [message #283958 is a reply to message #283952] Tue, 04 August 2015 16:37 Go to previous messageGo to next message
A Hamilto is currently offline  A Hamilto   United States
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Peer Oliver Schmidt wrote on Tue, 04 August 2015 16:12
I am in Farmville, seems to the center of nothing...

I gladly accept your offer for finding something for me. Smile

--
Best regards

Peer Oliver Schmidt
Lowes doesn't seem to have anything but EPS anywhere in VA. Home Depot everywhere in a 50 mile radius seems to have GAF brand in only 1/2" thickness at a little less than $12 per sheet. It would take three layers to fill 1-1/2".

That's the only polyiso I can find anywhere around Farmville. Which side are you on (N, S, E W) so I can find the closest store. All are probably going to be close to 45 miles one way.
Re: [GMCnet] Foam removal - PITA - Do I do things wrong [message #283961 is a reply to message #283958] Tue, 04 August 2015 16:50 Go to previous messageGo to next message
Olly Schmidt is currently offline  Olly Schmidt   United States
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Am 04.08.2015 um 17:37 schrieb A.:
> Peer Oliver Schmidt wrote on Tue, 04 August 2015 16:12
>> I am in Farmville, seems to the center of nothing...
>>
>> I gladly accept your offer for finding something for me. :)
>>
>> --
>> Best regards
>>
>> Peer Oliver Schmidt
> Lowes doesn't seem to have anything but EPS anywhere in VA. Home Depot everywhere in a 50 mile radius seems to have GAF brand in only 1/2" thickness
> at a little less than $12 per sheet. It would take three layers to fill 1-1/2".
>
> That's the only polyiso I can find anywhere around Farmville. Which side are you on (N, S, E W) so I can find the closest store. All are probably
> going to be close to 45 miles one way.

Near the Executive Inn.

So this
http://www.lowes.com/pd_304087-210-304087.0_1z11pq2__?productId=3122443&pl=1
is not what I want, even though it says it does not absorb moisture?

--
Best regards

Peer Oliver Schmidt
the internet company
PGP Key ID: 0x83E1C2EA


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Olly Schmidt
PGP Key ID: 0x18a9 3a1f 4196 bf22
'76a Eleganza II, VA
'73 Sequoia, SH, Germany
Re: [GMCnet] Foam removal - PITA - Do I do things wrong [message #283968 is a reply to message #283952] Tue, 04 August 2015 17:10 Go to previous messageGo to next message
Jim Miller is currently offline  Jim Miller   United States
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The polyisocyanurate board I used for my GMC came from Home Depot. They had it in multiple thicknesses.

Here’s a picture of it: http://www.jcmco.com/gallery/album01/abg

--Jim "saving the lives of Onans...one unit at a time" Miller
1977 Eleganza II
1977 Royale
Hamilton, OH


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Jim Miller 1977 Eleganza II 1977 Royale Hamilton, OH
Re: [GMCnet] Foam removal - PITA - Do I do things wrong [message #283971 is a reply to message #283961] Tue, 04 August 2015 17:51 Go to previous messageGo to next message
A Hamilto is currently offline  A Hamilto   United States
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Peer Oliver Schmidt wrote on Tue, 04 August 2015 16:50
Near the Executive Inn.
So this
http://www.lowes.com/pd_304087-210-304087.0_1z11pq2__?productId=3122443&pl=1
is not what I want, even though it says it does not absorb moisture?

--
Best regards

Peer Oliver Schmidt
I wouldn't, but you might not want to drive 50 miles one way to pay an extra 40 cents per 4 X 8 foot coverage and hassle with three layers instead of two for another r-2.8.

If you decide to get polyiso, the Lynchburg Home Depot store is 50 miles away, a couple miles closer than the Midlothian store. The number is (434)582-1619 to call and make sure they have enough in stock for your needs. GAF EnergyGuard 4 X 8' sheets.

7902 Graves Mill Road
Lynchburg, VA 24504
Re: [GMCnet] Foam removal - PITA - Do I do things wrong [message #283977 is a reply to message #283971] Tue, 04 August 2015 18:36 Go to previous messageGo to previous message
Olly Schmidt is currently offline  Olly Schmidt   United States
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A.

thanks for your findings. I guess I'll meditate over this a bit. Maybe
there are other reasons to go to Lynchburg or other Home Depot locations.

Thanks again!

--
Best regards

Peer Oliver Schmidt
the internet company
PGP Key ID: 0x83E1C2EA


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Olly Schmidt
PGP Key ID: 0x18a9 3a1f 4196 bf22
'76a Eleganza II, VA
'73 Sequoia, SH, Germany
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