Does anyone know of a product I could use to seal up some gaps i have around heater hose and wiring loom where they go through the firewall? I don't think there are any grommets that will fit and was thinking of a caulk sealant or expanding foam? Something that is flame proof and prefer something that doesn't harden like rock in case it needs to be removed later.
Why not get some of the caulking compound that is used between the tail-lights and body? You can cut it to length and wrap it around the loom, then squeeze it into position(it's waterproof and remains pliable enough to not crack with vibration).
Sikaflex or ploymer adhesive I would use sikaflex (typically used on cars during manufacture) for the job or a cheaper version is K&H MS polymer adhesive. If you use silicon make sure it is automotive grade which would also be neutral cure (normal silicon dries acidic and damages the metal after a long time). Available in tubes for caulking guns.
Take a look through this. Plenty of rubber grommets that will probably suit your application. http://www.spectrumrubber.com.au/images/stories/Spectrum_Rubber_Catalogue.pdf
use black sikaflex in a tube with caulking gun, as i have seen over the years it will out last a rubber grommet, depending on what the rubber grommet is made from however, a grommet is good though in a way as it can be fitted well for the purpose, sikaflex is messy, and once its on ya skin good luck getting it off lol
could use some seam sealer maybe? we use it to seal gaps in between panels when they get you ones put on ( ie : when installing new rad supports or beever panels )
