Author Topic: Rasp tracks  (Read 3828 times)

Offline WKevinD

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Rasp tracks
« on: July 10, 2017, 02:43:52 PM »
I just tried to finish a nice piece of tight, hard maple. Final shaping was done with a #50 rasp, and files and then scraped. I used overhead and side lighting. I then wiped it down with alcohol to raise any whiskers and scraped again.
After applying aqua fortis and letting it dry I used heat to set the color. That is when a couple of places on the forearm showed "rasp tracks", smooth to the touch but tracks just the same.
Any good suggestions on avoiding these in the future?
Kevin 
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Offline PPatch

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Re: Rasp tracks
« Reply #1 on: July 10, 2017, 02:55:49 PM »
I whisker with water, a damp towel or rag, wet but not dripping wet, works. Wet the stock, let it dry then continue working it. Also, take the stock outside and examine it in slanting sunlight holding it level with the eyes and turning it.

I have not tried it but some mix a few drops of yellow food dye in a pint of water and say that the yellow will highlight remaining marks.

dave
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Offline deepcreekdale

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Re: Rasp tracks
« Reply #2 on: July 10, 2017, 03:35:07 PM »
The yellow food coloring trick works great. I tend to use spoke shaves and drawknives for stock shaping and any finish shaping with files used only for wood working. This eliminates the problem entirely and is much faster to boot. When I used to use rasps for much of the shaping, I used to find many rasp marks during final sanding/scraping. Like Dave says, take it outside in sunlight and look at it from all different angles. I also like a bright shoplight from low angles during final scraping to look for flaws as well.
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Offline Joe S.

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Re: Rasp tracks
« Reply #3 on: July 10, 2017, 04:03:21 PM »
Ditto on the bright sun light,I thought taking the wood down in a hurry to speed things along did the oposite,now your chasing file marks,heavy grit sand paper ect.When I thought things where coming along the sun light said otherwise.

Offline Mike Brooks

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Re: Rasp tracks
« Reply #4 on: July 10, 2017, 06:01:10 PM »
I find a dull rasp will produce that effect. It is essentially bruising the wood, not cutting it.
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Offline jerrywh

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Re: Rasp tracks
« Reply #5 on: July 10, 2017, 06:39:25 PM »
 I don't know how good of a finish you want on your gun so I will assume you want it to be  very good.  Always when finishing a fine gun there are defects that show up along the process especially as the finish becomes smoother and smoother.  I learned this also as a body and paint man for 25 years.  You cannot see defects in a matte finish. This is why they texture sheet rock. Also you cannot see them under direct light because direct light does not cast a shadow.  In order to alter those factors when sanding anything smooth, and this includes carving background, The light must be  at a very low angle to the work just as you would shine a light along the floor or the side of a car when looking for defects.  Turn off all the other light when doing this.  This will help a lot but still as the surface becomes soother some more minor defects will show up because of the gloss effect.  There is nothing to do but deal with these as they appear.  Smooth finish is a real art.  All the other advise on this subject given is true as well in my opinion.  Especially on depressing the wood. Just my 2 cents worth.
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Offline Joe S.

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Re: Rasp tracks
« Reply #6 on: July 10, 2017, 10:00:13 PM »
I did notice areas that I snuck up on as in not getting to heavy handed with any of the tools used to remove wood including paper don't have any marks.Mike never really thought about brusising the wood but it does,put a dent in another non gun project and its as flat and perfect as it could be after reworking yet upon close inspection there's a mark.

Offline WKevinD

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Re: Rasp tracks
« Reply #7 on: July 10, 2017, 10:08:54 PM »
A bruise makes sense, I had hoped wiping with alcohol and whiskering would raise enough grain but a dullish rasp may well be compressing instead of shearing fibers. I think a yellow tint and outside light (if it ever stops raining) will be added to sending some files out to Boggs.
Thanks for the input.
Kevin
PEACE is that glorious moment in history when everyone stands around reloading.  Thomas Jefferson

Offline taco650

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Re: Rasp tracks
« Reply #8 on: July 11, 2017, 03:36:44 PM »
I don't know how good of a finish you want on your gun so I will assume you want it to be  very good.  Always when finishing a fine gun there are defects that show up along the process especially as the finish becomes smoother and smoother.  I learned this also as a body and paint man for 25 years.  You cannot see defects in a matte finish. This is why they texture sheet rock. Also you cannot see them under direct light because direct light does not cast a shadow.  In order to alter those factors when sanding anything smooth, and this includes carving background, The light must be  at a very low angle to the work just as you would shine a light along the floor or the side of a car when looking for defects.  Turn off all the other light when doing this.  This will help a lot but still as the surface becomes soother some more minor defects will show up because of the gloss effect.  There is nothing to do but deal with these as they appear.  Smooth finish is a real art.  All the other advise on this subject given is true as well in my opinion.  Especially on depressing the wood. Just my 2 cents worth.

I second the low angle light approach.  I use is all the time at work to find fingerprints on window, car doors, etc. as well as shoe prints in dirt ;-)

Offline thecapgunkid

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Re: Rasp tracks
« Reply #9 on: July 12, 2017, 12:29:30 PM »
Funny how I just went through this.  A new, sharp rasp and dedicated wood file, sunlight and lots of it helped a lot but I found the words of my opd shop teacher from high school in 19 something something worked best...use a patient, lighter hand and let the tool do most of the work.

Hope this helps

Capgun

Offline flehto

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Re: Rasp tracks
« Reply #10 on: July 12, 2017, 02:48:52 PM »
Because of my poor eyesight, a diluted orange toner from Jim Klein brings out any blemish. I use water to whisker the stock...alcohol doesn't quite do as good a job.
In addition, after the final staining w/ alcohol based stains is completed, a brisk rubbing w/ 0000 steel wool removes any errant whiskers and also removes any unabsorbed stain. I don't normally use AF or ferric nitrate. Just my preference....Fred




Offline WKevinD

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Re: Rasp tracks
« Reply #11 on: July 12, 2017, 03:56:19 PM »
I'll have to re-look at water instead of alcohol. I have been using alcohol because it evaporates so fast, when I think about it I really don't need speed but could use some work on my patience.
It makes sense that water would swell compressed fibers better than a fast dry.
Funny thing is a few decades ago I used water for whiskering and somewhere along the way I decided faster was better... probably before I retired.
Sometimes I need to go backwards to move forward.
Kevin 
PEACE is that glorious moment in history when everyone stands around reloading.  Thomas Jefferson

Offline PPatch

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Re: Rasp tracks
« Reply #12 on: July 12, 2017, 04:40:17 PM »
A bruise makes sense, I had hoped wiping with alcohol and whiskering would raise enough grain but a dullish rasp may well be compressing instead of shearing fibers. I think a yellow tint and outside light (if it ever stops raining) will be added to sending some files out to Boggs.
Thanks for the input.
Kevin

Bruised or dented wood can often be raised level with the surrounding wood by using a hot steam iron with a wet washcloth between the iron and wood at the spot in question. If you use this iron technique, and once dry, you still have a depression then that area will not ever improve - so it is back to wood removal to level the surface as best you can.

dave
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Offline Daryl

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Re: Rasp tracks
« Reply #13 on: July 12, 2017, 08:26:48 PM »
I did notice areas that I snuck up on as in not getting to heavy handed with any of the tools used to remove wood including paper don't have any marks.Mike never really thought about brusising the wood but it does,put a dent in another non gun project and its as flat and perfect as it could be after reworking yet upon close inspection there's a mark.

Here in BC, before a load of logs can be transported from a cut-block, a number of log butts in the load sticking out the back must have the timber mark stamp, hammered into the saw-ends.  The timber-mark hammers are like sledge hammers, with the timber marks on them.  They are very visible, and if a foot or two of log is cut off to remove the timber mark, it will still show to a side light.

 This is similar to what Mike was noting, about bruising the wood and still showing although the surface is flat.
Daryl

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Offline jerrywh

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Re: Rasp tracks
« Reply #14 on: July 12, 2017, 09:56:55 PM »
 There is also something to be said about using the color coat approach.Custom Auto body painters often use a fog paint they call it to show the defects in a panel before applying the finish paint.  This would be the same thing as using the yellow die technique spoken of previously. The yellow die or any other color that is on the wood will be left in the low spots when sanding  and make them visible.  This only works well when block sanding because without some sort of support for the sand paper it will not level the low spots very well. If you don't use block for sanding you will always have trouble with ripples.
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