Hey,
I have a problem using my card scrapers. They cut very good at first pass (50 cm or 20") but at second they only produce dust and I have re-establish the hook. Cabinet scraper in contrast last much longer (in fact I only burnished it once).
The only difference I can think of is steel thickness (1 mm for cabinet and 0.4 / 0.6 mm for card). Could it be overheat during work causing that? Less steel to sink heat, long pass and I've recently used veritas scraper holder. Is overheating usually a problem for scrapers? Should I pay attention to that and check it after each pass, what would be you rule of thumbs here?
Another confusing moment is that I was removing old finish with scraper. Will it affect performance or it should be pretty similar to scraping bare wood? Will the type of finish matter?