Disaster w/insulation

I am having a horrible time trying to glue the polyiso onto the metal. I have wiped it down with alcohol, used M77 &m and m90. Used 1" side walls, really hard to find 1/2", same on roof. then did find 1/2" over ribs. will not glue. In CA not cold. With 1" some stuck but some areas had 1/3" gap. Tried spraying into gap and used wood slats to keep it tight. Removed slats and it came back down right away. I decided not to worry about gaps and tried 1/2"over it. Roof doesn't stick much. Enough that I pulled it right off. Cleaned glue off of ribs, 1" leaves gap so no contact. wiped down insulation and ribs to remove old glue supported over night and part of day, didn't stick at all. Okay, try screwing down with self pierciing sheet metal screws. They don't go through metal. Tried pre-drilling with titanium bit, several  and types of screw heads. Hex heads the best so far but don't want to lay back against. No prob with pan head once drilled so will use them. Finally got a couple through with light pressure or a tremendous amount of pressure. Extremely difficult. I have cut all insulation, wood for walls, used 1/8th" plywood for walls but can't put it on without glue. To prevent mold have sealed panels with spray foam insulation and metal tape to prevent change of temp between metal and insulation and am using Kills to prime wood to kill mold. I am supposed to be at my sons wedding on 10/19 and don't think I will make it. Have been working on this for weeks now. Any suggestion????? OMG! Help!!!!

Pictures please!!! Is the glue sticking to the insulation? Are you spraying both surfaces with the glue? are they flat surfaces? Tnttt.com foamies section has a section on how to glue foam to other surfaces that might help. Sometimes glue will not stick well to a slick surfaces unless both surfaces are very lightly sanded, wiped clean and dried.

3M 77 and 3M90 are contact adhesives. They don't work if the two surfaces are not in direct contact with each other. So if you have a gap you need to switch to a different method of installation that does not involve contact adhesives.

For instance: you can apply tape to the surface of the foam and have that tape extend onto the metal surfaces to hold it in place. This will require the least amount of labor of the solutions I am presenting to you.

You can do a tight pressure fit by making the insulating panel very slightly oversized so that when installed they press against the sides of the cavity. This is not overly labor intensive but does require careful measuring. If you cut a piece too small you can glue or tape a scrap of foam to the edge to rebuild the width of the panel.

You can use battens to keep the sheets retained in the cavity. Fastening the battens to the ribs of the structure. Then when you apply your interior wall sheathing it can be attached to those battens. Labor intensive but it is a solution many people prefer.

There are some types of thick adhesive caulks that will do a quick grab. Just remember that caulk needs a way to dry and the metal of a van is not absorbent of moisture and the foam is also not absorbent. So you can't put a wide area of caulking on those surfaces and expect it to dry all the way through. On a wide area of caulk the edges dry and that prevents the inside area from curing which means not a lot of strength to the bond. So your lines of caulking should be an inch or so apart and the gap the caulk has to span should not be any larger than what is specified on the tube of caulking. One way around this is to apply wood battens to the surface of the metal. The thickness of the battens can be adjusted to provide a more level area of contact for the foam sheet. It is OK if there is a gap between the battens, you can level that up with some of the thin foam used for placing on sill plates when framing up a house or you can just leave that space to have a void. Then when you apply your sheet of foam you only apply adhesive to the surface of the battens and to the foam where it touches the battens.

Thank you so much for the options. I think maybe the tape might be a good option. I understand they have to have contact for the glue to stick and some does and in other areas there is a gap so the only thing it can stick to is the ribs. I did try the caulking type of glue but maybe didn't use enough. The polyiso does have an aluminium moisture barrier on both sides so maybe it is too slick but I can't scuff it up. I do have the adhesive on both sides and waited for it to get "tacky" before sticking it. I have spent so much money trying to find something to work. Maybe the tape would be affordable and easy to apply. I am not sure exactly what type of tape to use but I can probably find out. thank you so much!

How large are the sections you are trying to glue? if they are too big, the weight of the foam might not let the glue set unless you clamp it and let it set.

If you cut into smaller sections it will be lighter and it should hold without clamping.

If you just want to do it quickly get a hotglue gun and cut in small sections and install. Its all I use in my van. Hotglue drys in minutes and its a permanent job. On the roof I have 6 layers of 1/2 inch foam, its been installed going on 6 years, never had any come loose no matter how hot it gets. Hotglue sticks extremely well to foam and metal. You can get a hotglue gun for 20 dollars and use the generic gluesticks.

Picture of my roof, notice how the sections are small, reason for that is hotglue drys quickly, if the sections are too big, some areas might dry before you apply it all.

Yes with foil on both sides do not try to scuff it up! You are basically trying to glue metal to metal.

I  have no idea why its being done that way.  We used cork rolls for flooring.
Cheap, sound proof, water proof and mold proof.

This stuff https://corkdirect.com/premium-cork-underlayment/

You would need the 1/2" thick to get any substantial Rvalue out of that material.

"Maybe the tape would be affordable and easy to apply. I am not sure exactly what type of tape to use"??
I used adhesive that did not work but the tape held in place and I did use a few battens to put up the plywood sheets. Be careful with your screw length so you don't go all the way through.  The tape I used was the aluminum tape used with reflectix about 3 dollars a roll at Home Depot.    -crofter

I was hoping not to put more wood over the insulation, but I think I will at least need a few battens screwed into the cross members of the roof to keep everything up there. Any better advice or links? I am using the pink stuff and have tried the manufacturer's expensive glue, why I went with battens and wood on the walls. I like the performance of the pink stuff with good results on insulation and sound deadening.  

https://www.buildsite.com/pdf/owenscorning/FOAMULAR-250-Installation-Instructions-1679591.pdf

https://www.googleadservices.com/pa...MIz8qrvdPC5QIVkONkCh0XyAAGEAQYBCABEgKPM_D_BwE


Owens Corning FOAMULAR 2 XPS insulation, I am using 1 inch in the ceiling.

Manufacturer reccomendation is vague about adhesives: "Secure FOAMULAR® Insulation with construction adhesive compatible with polystyrene or foamed plastics as noted by its manufacturer (follow adhesive manufacturers’ application instructions). • Apply FOAMULAR® Insulation to wall within 15 minutes after adhesive is applied."
~crofter

I found this video and they are using battens to hold it in place after putting it up with adhesive.



the second video shows some washers that are used to attach foamboard to metal studs, so no need for battens. Fasteners with the attached plastic washers at the hardware store. 



The third video shows application to the ceiling using Crest adhesive and also fasteners, and taping the joints also 
standard with manufacturer's recommendations


Lowes recommends this for use on metal surface: LiquidNails Project
[font=Helvetica, Arial, sans-serif][size=small]Liquid Nails project, 10 Oz, off white, construction adhesive, interior grade, waterproof, will bond to almost any common building materials including plywood, hardwood, furring strips, paneling, ceramic fixtures, drywall and molding, VOC compliant, rubber based/high solids formula, VOC compliant, replaces TV #284-307 for members in VOC restricted areas.[/font][/size]

• Strong, durable bond
  
• Ideal for interior use
  
• Low odor
  
• Easy water clean-up
  
• Non-staining
  
• Will not attack foam insulation
  
• Up to 30 minutes working time
  
• Exceeds ASTM C-557
  
• Meets the GREENGUARD Gold Standard
  ~crofter

Did you try the self sticking insulation spikes?

Can you post a pic or link for these? That might be a good option for some.    ~crofter

It was a really warm day today, so I put up 1 inch XPS on the van roof today. THe XPS is durable, moisture proof, and easy to use. After chatting with Lowes, I decided to use Liquid Nails projects glue. 3 tubes for one sheet I put it on pretty thick. If you read the label on Liquid Nails Projects  it is recommended for foamboard, and also not recommended. Well that's silly. I will let you know how it sticks.  ~crofter

Materials I used:

View attachment 24868


[font=Tahoma, Verdana, Arial, sans-serif]Sticks wedged in pressing the XPS sheets onto the ceiling in my van.[/font]

The XPS will be covered with reflectix layer, seems to make a big difference and I like the bright look of it.  Some would choose the 1/8 inch wood panelling for a darker look.   ~crofter

Mmmm... very interesting! Panel with reflectix. I love it. May I steal your bright shiny van interior idea? I'm using Thinsulate SM 600L for insulation. R value is 5.2 ... Very pricey but so easy to install using spray adhesive. When done I'll use what's left over to sew inside curtains.

The 1 inch XPS panel is R5 (on the ceiling) but I put R10 XPS in the walls. ~crofter

So my Liquid Nails Project glue is still drying, according to the info I found online, should be done sometime this afternoon and I can take the bracing out then. The glue seems to be well adhered to the metal side, and the foam should be as well. My last try with this insulation and the manufacturer's glue I had the expectation of the glue being set in a few minutes, probably why it initially fell off the walls (now being held in place by other layers of the wall installation). Online info about cure time:

"[font=Roboto, arial, sans-serif]Wood [/font][font=Roboto, arial, sans-serif]glue[/font][font=Roboto, arial, sans-serif] sets in a little as 15 minutes for basic joining of woods, but requires 24 hours before applying any type of stress to the [/font][font=Roboto, arial, sans-serif]glued[/font][font=Roboto, arial, sans-serif] area. [/font][font=Roboto, arial, sans-serif]Liquid Nails[/font][font=Roboto, arial, sans-serif] recommends bracing or clamping the adhered surfaces for 24 hours, taking a full week to completely [/font][font=Roboto, arial, sans-serif]cure[/font][font=Roboto, arial, sans-serif] to maximum strength"[/font] 

~crofter

travelaround said:

Mmmm... very interesting! Panel with reflectix. I love it. May I steal your bright shiny van interior idea? I'm using Thinsulate SM 600L for insulation. R value is 5.2 ... Very pricey but so easy to install using spray adhesive. When done I'll use what's left over to sew inside curtains.

Click to expand...

Can you post a pic or link about your process with the thinsulate insulation? And where did you find the 600 Thinsulate, I am not finding that online? I saw some for sale at Joanne's fabric shop and it looked interesting, but no idea came to me about how to use it in a van build.   ~crofter

https://www.joann.com/54in-ivory-warm-window/10674935.html#q=thinsulate+insulation&start=1
[font=avenir-regular, sans-serif]"This lining keeps in up to 80% of heat normally lost through windows in winter, and blocks up to 79% of the unwanted solar heat providing a comfortable ambience" 

Thinsulate carried by Amazon:
https://www.amazon.com/Fields-Fabri...t=&hvlocphy=9032842&hvtargid=pla-655515469097

[/font]No R value listed on the Amazon site, but an internet search tells us this (thanks Google):

[font=arial, sans-serif]"What is the R value of Thinsulate?[/font]
[font=arial, sans-serif]It retains its insulating properties when wet. The thermal resistance R-value provided by Thinsulate products varies by the specific thickness and construction of the fabric. Values (US units) range from 1.6 for 80-gram fabric to 2.9 for 200-gram fabric."[/font]

 If the R values add, then your 600 fabric would have an R value of about R9, that's pretty good. I can use the cheap foamboard because my van is so square, but for a curved outline, this might work better.    ~crofter