Most spray adhesives list foam, but that doesn’t mean foam board. Of the cans we read, only 3M 78 says it won’t dissolve polystyrene, and Gorilla’s Ultimate and Loctite’s Professional 300 say not to use them on it.
Each can, in its maker’s words
| Can | Bonds | Polystyrene foam | Bond |
|---|---|---|---|
| 3M Super 77 | Foils, carpet, many lightweight foams, paper, cardboard, felt, cloth, to metal, wood and hardboard | Not stated | Bonding range 15 seconds to 15 minutes |
| 3M Hi-Strength 90 | Decorative laminates, particleboard, even polyethylene and polypropylene | Not stated | Contact-type; bonding range 1 to 10 minutes |
| 3M Foam Fast 74 | Flexible foam and fabric, to wood, metal, fabric and non-vinyl plastics | Not stated | Dry time 30 to 60 seconds |
| 3M Polystyrene Insulation 78 | Polystyrene insulation | Bonds it without dissolving or degrading | Industrial cylinder |
| Loctite Multi Purpose | Paper, cardboard, foam, fabric, leather, felt, cork, foil, certain plastics, metal, glass, wood | Not stated | Open time 1 to 10 minutes |
| Loctite Professional 300 | Plastics including polypropylene, acrylics and PVC | Not recommended | Can’t be repositioned |
| Gorilla Heavy Duty | Paper, cardboard, foam, fabric | Not stated | Repositionable up to 10 minutes |
| Gorilla Ultimate | Lists car headliners, foam and rubber | Not recommended | Permanent; not repositionable; 32 to 180°F |
| DAP Weldwood Multi-Purpose | Plastics, paper, felt, foam, metal, cardboard | Not stated | One surface removable, both permanent; 0 to 150°F |
| Permatex All Purpose | Upholstery, carpet, insulation | Not stated | Permanent and repositionable |
From each can’s page or data sheet. Loctite’s Multi Purpose page lists polyethylene and polypropylene, but its data sheet says only “certain plastics”; we go by the data sheet.
Foam: read the can, not the word
“Foam” on a can doesn’t say which foam. 3M lists “many lightweight foams” for Super 77 and says nothing on polystyrene; Gorilla Ultimate lists foam and also says not to use it on polystyrene foam. Where a can says nothing, we’d test on a scrap of the foam first.
Gorilla’s own line splits on headliners: Heavy Duty says not for automotive headliners, while Ultimate lists car headliners.
Using one
- Permanent: DAP says to spray both surfaces of its Multi-Purpose for a permanent bond. Gorilla says to coat both surfaces of Heavy Duty and let them dry to tack, about 1 minute.
- Removable: DAP says one surface for a removable bond with its Multi-Purpose.
- Heat: 3M lists a shear adhesion failure temperature for its cans; that’s a lab test, not a rating for use. Gorilla Ultimate gives 32 to 180°F and DAP’s Multi-Purpose 0 to 150°F.
Gorilla’s Heavy Duty and Ultimate, DAP’s Multi-Purpose and Loctite’s Multi Purpose carry “Danger”. We’d spray outdoors or with strong ventilation, away from flame. Gorilla says its Heavy Duty spray isn’t for direct or indirect food contact.
Brushing it on instead?
Contact cement