Scrapers

[johnleeke]

Square End Panel Blade Paint Scraper – 145-A:

Stortz tools are well-known for their quality. At $12 each these scrapers do not seem over-priced. Their only downside is the wide acute bevel. As I use and re-sharpen this scraper I made a narrower and more obtuse bevel that controls the cut and make an edge that lasts longer. They are Made in America, and I now recommend the Stortz scraper over Marshalltown's scrapers, which are made in China.
This scraper is good for removing softened putty during deglazing, cleaning out the glazing rabbet and removing paint from sash tracks. The slightly acute angle on the wide end is especially useful for cleaning out interior right angles.
More info and source: http://www.stortz.com/OnlineStore/Produ ... raper.aspx

[johnleeke]

Sash Profile Scraper

(Updates: 3/14/17 video preview; 8/5/15 expanded procedure, materials & tools; 8/1/15 scraper sources; 7/14/15 now editing video to be posted soon)

Here is the Sash Profile Scraper in action (click on the back button of your browser to return here after seeing the video):
https://youtu.be/VzqnEm24ajQ?t=11m23s


Video: Making a Sash Profile Scraper, 27 min.

How to make a custom profile scraper to efficiently and effectively remove paint from the molded profile of window sash. It takes me 60 minutes to make a profile scraper that exactly matches the profile on a sash. I recover that time if there is more than 5 lineal feet of molding to scrape. After that the scraper reduces molding scraping time to one-fifth the time it takes doing the scraping piece-meal.

Procedure

1. Remove paint from stile of sash in a 3" long section down to bare wood, be careful to not damage the wood.

2. Prepare the blade by grinding off extra steel at a 65 degree bevel.

3. Determine the angle of the scraper. Set the edge of the scraper blade on the wood profile, swing the handle out 35 degrees and up 35 degrees. Memorize and learn this position for the scraper. Make a cardboard 35 degree gauge as show in the video to help you learn the angle.

4. Scribe the profile from the sash onto the scraper blade. First coat the face of the blade with felt-tip pen ink (Sharpie Pen). Set the blade on the wood profile, and scribe the shape of the wood onto the face of the blade with a machinist's scribe.

5. Grind down to the scribed line, forming a 65 degree bevel at the scraping edges and a round shape on the safe edges.

6. Refine the shape of the scraping edges by comparing the shape of the edges against the wood profile and grinding away the high points. If the scraping edge is way off, then repeat 4. & 5. If the shape is close grind a small amount more carefully with a Dremel tool.

7. Round off the safe edges with a flat jeweler's file and polish them with emery cloth or wet-dry sandpaper.

8. Sharpen the scraping edges with careful hand filing using jeweler's files.

9. Sharpen the flat edges of the scraper blade with a sharpening file.

10. Scrape paint off a short section of the sash to test the scraper's performance. If the scraper leaves stripes of paint, refine the shape of the edge with the Dremel too or jeweler's files. Check to see if the safe edges are scoring the wood, if so, refine their shape with the jeweler's files.

11. Have some fun scraping paint off of a sash with your new Sash Profile Scraper.


Materials

Pull-type scraper with carbon steel blade
MarshallTown E1241 19691 - Molding Scraper

We need the handle, it is only available with the triangle blade, which is not needed for this work.
Source: ToolUp website, https://www.toolup.com/MarshallTown-E12 ... -1-4-Blade

MarshallTown E1247 19697 - Cyma Blade

We will re-shape the ends of this blade to match the sash molding profile.
Source: ToolUp website, http://www.toolup.com/MarshallTown-E124 ... Cyma-Blade

Felt-tip marker, black (thick line Sharpie)
Source: your local hardware store

Emery Cloth or Wet-dry sandpaper, 400 grit, 600 grit
Source: your local hardware store

Thin cardboard, for the angle gauge

Tools

Machinist's Scribe

General Tools & Instruments, 380B Two-Point Scriber
Source: Amazon.com, http://amzn.com/B0031EQQDC

Small Flashlight
Source: your local hardware store

Dremel Tool (grinder)
Source: your local hardware store

Fiber-mesh Grinding Blade
Du-Bro 352 1-1/4" Cut Off Wheel (2-Pack), Get this particular product because the Dremel brand cut off wheel is too brittle and may break during this use.
Source: your local hobby shop, or Amazon.com, http://amzn.com/B0006O4GXM

Jeweler's Files

General Tools & Instruments, 707476 6-Piece Swiss Pattern Needle File Set. The half-round tapered file and flat file are the two most used.
Source: Amazon.com, http://amzn.com/B000NUCAZA

Sharpening File

Hyde Tools 11200 Sharpening File
Designed to sharpen carbon steel scraper blades. Double cut tooth pattern. This file produces a surface with slight grooves, unlike an ordinary mill file that produces a smooth surface. This results in a stronger and more aggressive edge on the scraper.
Cost: about $14
Source: Amazon.com, http://www.amazon.com/Hyde-Tools-11200- ... B001NOEE7M

Scissors, to cut the angle gauge cardboard

Metal Protractor (if needed)

Source: your local hardware store, or Amazon.com: http://amzn.com/B00004T7TB

Bench Grinder (if needed)
If you have one use it, otherwise the Dremel grinder will work, but will be a bit slower.

...more to come...

[johnleeke]

I consider it a scraper if it has a 25-35degree bevel with a simple burr left from grinding, and a "hook shave" if the bevel is ground at a very low angle and a hook-shape is formed along the edge with a burnisher. The hook shave is far too aggressive because it more easily gouges into the wood. In my window work I used a scraper, which causes less damage because the bevel protects the wood from damage.

Image Source: http://workshopcompanion.com/KnowHow/To ... rapers.htm

[johnleeke]

I customized the Stortz triangle scraper for sash deglazing:
-- ground two corners to a slightly less than 90 degree angle for removing front putty
-- ground a profile on the other point to match the typical ogee profile
[attachment=0]1566400992294.jpg[/attachment]

[johnleeke]

Jonathan Appell's Atlas Preservation website carries the best selection of Lawson putty knives:
https://atlaspreservation.com/collectio ... int-knives
Jonathan also carries a wide selection of molding scrapers, the famous Stortz scrapers and the old standby Marshalltown scrapers:
https://atlaspreservation.com/collectio ... ers-blades