While reading build alongs and watching videos I see some folks working their tiller while the bow is strung up.  Is this common or is it more of a mastered skill?  Will the bow react that quickly to a little sanding while its strung up or does it need worked a few pulls to check to see results?

No better way to keep an eye on things then tillering your bow out while it's strung up Matt. Never done it any other way. But then again, my tillering is pretty much done once I get my string on and all I'm looking at is reducing weight.........Art

I leave bows strung once I am close on weight.  After a bow has been trained to bend, corrections will register very quickly but, yes, pulling it several times helps it settle and gives me my truest reading.  I call it exercising and generally go 30 pulls to the draw length I am up to.

So I have been scraping, stringing, unstringing, scraping, stringing, unstringing for nuttin'? I read a few times in a few places to never remove wood from a bow when its strung.....dang....

I used to do it quite often, but stopped after cutting a string once.  Bow hit the ceiling of my shop.

wow No-sage, I can only imagine.  Luckily it just went up.

PD, I have been reading so much lately and it seems some things that one person says is the total wrong way to do something, is the only way another person does it.

I read the same. I also know guys like John, Pat, Art, Roy and so on have built bunches of bows. I just absorb info from what I consider trusted sources! We all have valid opinions, just some of us have "been there done that already".

I do too unless the outer third of the limb needs work. Then I unstring to keep from nicking the string.  Jawge

I forgot George, he has made a couple bows as well! The thing to remember is there is always more than one way to skin a cat, some are just easier!

Yup I remove wood from my bows while strung. Then excerise them 30 times and re-check.

I have a 12" 1x2 with a string notch in one end and a concavity in the other to hold my bows partially drawn while I scrape.  Still, my older tillering string shows some wear from the back of the scraper hitting it  

I just can't imagine any reason why this would harm a bow in the making.  But I'm open to suggestions.

pearl- ive been doing the same thing. unstring and scrape- ive been too worried about cutting a string!

My concern wasnt the string getting nicked as much as it was removing material while the belly was under compression. I am going to start leaving my string on. That will save me alot of extra work. Good thread Matt!

LOL, might help you a bit in the tillering process there Pearl Drums.  And will surely make it go quicker  

Isnt that the truth Nathen!

i've always unstrung before scraping/sanding... guess it was unnecessary? I just felt safer by doing it, and I was a bit concerned with nicking a string. My routine would be:

String
Draw to tillered length 30 times
Draw on tillering stick
Eyeball it
Use the tillering gizmo
Take off stick, unstring
Scrape/sand

Repeat.

Guess I can cut two steps out of the process, eh?

thats exactly how i do it too

Ole Pearly Boy never wuz too smart:) LOL

Tillering with the bow strung is the reason I put duct tape on the top side of my scrapers, bowyers edge, and other tillering tools; it keeps me from nicking the string.

Good post, never thought of that. Seems to make sense but I still feel a bit reserved about it unless I was really close to my final draw weight. Definitely something I will try on my next one.