Card scraper question

[Alexander Zagubny]

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?

[glenn bradley]

Although I have done it for spot fixes, I do not think a card scraper is the right tool for scraping finish. A carbide scraper (https://www.amazon.com/Warner-Carbide-Scraper-Knob-807/dp/B000H7KY0W/ref=asc_df_B000H7KY0W/?tag=hyprod-20&linkCode=df0&hvadid=198091577722&hvpos=1o5&hvnetw=g&hvrand=7687009800891677461&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9031488&hvtargid=pla-348885267816&psc=1) would be more appropriate.

I have card scrapers that are quite stiff all the way down to ones that I can flex between the fingers of one hand to scrape veneers or inlay. All hold an edge about the same when used as intended.

[Robert Engel]

Personally I find thicker card scraper to last longer. I don't see an issue using one to remove finish like shellac, but a hard finish like polyurethane will wear it out quickly. Certainly not a thick finish or paint. I usually go to my No. 81 scraper for this.

Most issues with scrapers are related to prep technique.

What hook angle are you using? If the hook angle is too steep, the burr will roll over and/or break off fairly quickly. Sounds like this is what's happening.

Very important step is drawing out steel almost parallel to face prior to turning the hook.

William Ng has one of the best card scraper videos out there. Check it out.

[Alexander Zagubny]

Thanks! I've checked the video and I think that too large hook might be my problem. Otherwise I use similar technique.

However with cabinet scraper the hook is large...
I will probably check it with microscope next time, just to understand what is happening.

[john zulu]

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?

What brand are you using? Mine last pretty long. What wood are you using it against?

[Lee Schierer]

I struggled with my scrapers for quite a while. Then someone here suggested trying the technique shown in this video (https://www.finewoodworking.com/2012/10/24/how-to-sharpen-a-card-scraper). My results since then have been much better.

[chris carter]

This video is when I went "ohhhh, now I get it!"

https://www.youtube.com/watch?v=hMuaGqSMjIs&t=438s

[Terry Beadle]

Very well done!! Thanks!

[Alexander Zagubny]

Thanks everyone for replies and videos!

I think I will add checking sharp edge (without burr rolled over) against pine to my process. And also will pay attention to angle between burnisher and edge (pushing metal to right direction), that makes sense.

I have one veritas scraper and some unknown brand from local shop. Blade for cabinet scraper was made from unknown brand. Not sure if brand really matters, the all seems to be good enough. Probably I should have sharpened veritas one as well despite instruction saying it's ready for burnishing. But I don't have convenient sharpening station as for now so was a bit lazy to do it.