They sell it in kits and the 1 kilogram package is as small as it gets.

I've been using Belzona in an industrial setting since 1982. It is an industrial product for industrial use. With the material you can usually get an in-plant demonstration by a tech rep, and training for the people who will be applying it.. The early '80s price, IIRC, was $165 per kit.

Belzona is not intended for hobbyist use.

R.

PS: That old wives' tale about "warping the valves" is just that, a tale. It's not true. It probably came from someone overthinking the situation. I have heard it since I began to be interested in cars in the '60s.
As a youth I helped haul grain from the field and augur it into bins. Our grain augur had a Wisconsin AGND single cylinder gas engine. After a couple of years of use the muffler burnt off. I remember many a dark night as I unloaded the last truck of the day, standing directly behind the exhaust port and looking at the exhaust valve at yellow heat. There was about an inch between the edge of the block and the exhaust valve. Year after year the muffler didn't get replaced and I can attest that the engine compression was as strong as ever. No warped valve for this engine!