Re-pin and Tighten Loose Sash Joints (final)

Wood repairs for sashes, frames and sills.
Bob Yapp
Posts: 59
Joined: May 9th, 2011, 8:39 am

Re-pin and Tighten Loose Sash Joints (final)

Postby Bob Yapp » February 15th, 2012, 2:06 pm

Author: Bob Yapp
Contributors:
References:

Title of Treatment: Re-pin and Tighten Loose Sash Joints

Class of Treatment: [ ] Maintain, [ ] Stabilize, [x] Repair, [ ] Upgrade, [ ] Exception

Type of Treatment: [ ] Traditional, [x] Modern

Condition to be Treated:

Loose mortise & tenon joint on a sash. Often the wood of the joint is in good condition, but there is a gap at the loose joint.

Description:

If the joints are solidly together yet a bit loose and the tenons are in good condition, the mortise and tenon joints can be re-pinned without taking them apart. In many cases disassembling the sash is not necessary. To successfully re-pin a loose mortise and tenon joint the glass must be removed from the sash first. New mortise and tenon pinning is best done from the interior side of the sash to reduce potential water entry holes on the exterior face. Stainless steel pins will not corrode.

Typical Procedure:

1. Remove the glass panes from the sash.
2. Remove all paint and finish residue from the gaps in the joints on both faces of the sash using dental picks or a utility knife. Be careful not to remove any wood from the joint. Clean out all remaining debris from the gap with a vacuum.
3. Clamp the sash in both directions next to the tenons but not over them. Tighten the clamps until the gap at the joint is snug. Set the clamp jaws so the exterior side of the sash lays flat on the work table or bench.
4. Square the sash. Test for squareness at all four corners with a try square or carpenter's square. Adjust the clamps until the sash is square over all.
5. Clamp the first joint, on each side of the mortise and tenon joint, flat to the table. This keeps the driven pins from pushing wood out the exterior side of the sash.
6. Select a steel pin that is 3/8" shorter than the thickness of the sash. Pins should not have a point on the ends as they will split the wood when driven into the joint.
7. Cut the head off a finish nail that is slightly smaller than the diameter of the pin. Use this nail in a drill to create a pilot hole for the pin. Do not use a drill bit, which removes wood by cutting. The nail ploughs through the wood and the fibers can then squeeze back around the pin, holding the pin in place.
8. Drill two pilot holes through the interior face of the sash, through the tenon and just into the bottom side of the mortise. Angle each pilot hole at an opposing angle of about 7 degrees to each other.
9. Drive the two pins into the pilot holes and set them 1/8" below the surface with a nail set. After priming fill the pin holes with glazing putty.
10. Repeat the procedure above for each loose mortise and tenon joint on the sash.
11. Check to assure all mortise and tenon joints are tighten up and the sash is square.

Materials:
• Stainless steel pins
• Finish nail

Quality of Results:

Best Work:
Joints are tight. The sash is square. The pins go through the body of the tenon and into the bottom side of the mortise, and do not come through the exterior face of the joint. Pins are set and holes filled with putty.

Inadequate Work:
Open gaps in the joints because some debris was not removed from the joint. Joints are still loose. Sash pins were installed from the exterior face. The sash is not square.

johnleeke
Posts: 375
Joined: April 13th, 2011, 7:34 pm
Full Name: John Leeke
Location: Portland
Organization: Historic HomeWorks
Permissions: Yes
Location: Portland, Maine
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Re: Re-pin Mortise & Tenon Joints (draft)

Postby johnleeke » February 25th, 2012, 5:32 pm

OK, I gave this one a pretty heavy edit, but I think it's more concise and usable. Please check it over closely to make sure it's still correct.

I'd like to include a little more about the stainless steel pins. What is the diameter and available lengths?

These pins are not available through the usually window or construction suppliers. Can you say anything about what they are made for, that would help readers track them down?

I removed the references to galvanized pins and pins with points, because I want to submit a standard on pinning joints in a traditional way with this traditional type of pointed pin. It's essentially the same as this procedure, with an added step or two and comments about the galvi pointed pins. Bob, is it OK with you if I just copy this procedure, and add a few changes to it?
John
Standards Co-Founder
Standards Editor

http://www.HistoricHomeWorks.com

Bob Yapp
Posts: 59
Joined: May 9th, 2011, 8:39 am

Re: Re-pin Mortise & Tenon Joints (draft)

Postby Bob Yapp » February 25th, 2012, 6:16 pm

Good edits. If you're going to use this stuff for a galvanized pin, that wouldn't be traditional either. Even older steel pins rarely have a point on them and I cut the point and head off when using a #6 hot dipped galvanized casing nail as a pin.

johnleeke
Posts: 375
Joined: April 13th, 2011, 7:34 pm
Full Name: John Leeke
Location: Portland
Organization: Historic HomeWorks
Permissions: Yes
Location: Portland, Maine
Contact:

Re: Re-pin Mortise & Tenon Joints (draft)

Postby johnleeke » February 25th, 2012, 6:55 pm

Most of the old steel pins I pull out here in New England have points. I have also seen pointed pins in Idaho and Florida. It's probably highly regional. Lets do a poll to see whats happening around the country.

Do you see pointed or blunt pins, and where are you located?

Do you see steel pins or wood pegs, and where are you located?


I've been setting steel pins in this traditional way:

I make the pilot hole with a brad awl. The awl has a sharp edge across the end that I set on the surface across the grain. As the awl is pushed into the wood it is rotated slightly and the edge cuts the wood across the grain and the awl compacts the wood against the side of the hole. The resulting end grain of the wood along the sides of the hole is all pointing downward. When the pin is put in the hole, and the wood expands back and against the pin, the downward pointing end grain wood "grips" the pin to keep it from backing out--a lot like old hand-wrought spade pointed nails or later cut nails worked.

I came across this in an old trades manual when I first made sash with steel pins back in the late 1970s. The manual was describing how windows were made in the factory (c. 1890s), and it showed the device that shoots the pins. But there was a chapter on hand work at the bench. The sash pin detail for hand work with the brad awl was in that.

In any case it works.

Galvi pins weren't common, but I have seen them twice. I can't recall the dates on those places, but definitely first half of the 20th century. The zinc in the galvi coating has an interesting effect on the surrounding wood. If the wood and galvi get damp some of the zinc goes into solution and soaks into the surrounding wood helping to protect it from decay.
John
Standards Co-Founder
Standards Editor

http://www.HistoricHomeWorks.com

johnleeke
Posts: 375
Joined: April 13th, 2011, 7:34 pm
Full Name: John Leeke
Location: Portland
Organization: Historic HomeWorks
Permissions: Yes
Location: Portland, Maine
Contact:

Re: Re-pin Mortise & Tenon Joints (draft)

Postby johnleeke » February 27th, 2012, 5:21 pm

Bob, do you want to describe the stainless steel pins in more detail?


I'd like to include a little more about the stainless steel pins. What is the diameter and available lengths?

These pins are not available through the usually window or construction suppliers. Can you say anything about what they are made for, that would help readers track them down?
John
Standards Co-Founder
Standards Editor

http://www.HistoricHomeWorks.com

Bob Yapp
Posts: 59
Joined: May 9th, 2011, 8:39 am

Re: Re-pin and Tighten Loose Sash Joints (draft)

Postby Bob Yapp » August 27th, 2012, 12:54 pm

John, I think this is good to go. I made a couple of slight changes in red


Author: Bob Yapp
Contributors:
References:

Title of Treatment: Re-pin and Tighten Loose Sash Joints

Class of Treatment: [ ] Maintain, [ ] Stabilize, [x] Repair, [ ] Upgrade, [ ] Exception

Type of Treatment: [ ] Traditional, [x] Modern

Condition to be Treated:

Loose mortise & tenon joint on a sash. Often the wood of the joint is in good condition, but there is a gap at the loose joint.

Description:

If the joints are solidly together yet a bit loose and the tenons are in good condition, the mortise and tenon joints can be re-pinned without taking them apart. In many cases disassembling the sash is not necessary. To successfully re-pin a loose mortise and tenon joint the glass must be removed from the sash first. New mortise and tenon pinning is best done from the interior side of the sash to reduce potential water entry holes on the exterior face. Stainless steel pins will not corrode.

Typical Procedure:

1. Remove the glass panes from the sash.

2. Remove all paint and finish residue from the gaps in the joints on both faces of the sash using dental picks or a utility knife. Be careful not to remove any wood from the joint. Clean out all remaining debris from the gap with a vacuum.

3. Clamp the sash in both directions next to the tenons but not over them. Tighten the clamps until the gap at the joint is snug. Set the clamp jaws so the exterior side of the sash lays flat on the work table or bench.

4. Square the sash. Test for squareness at all four corners with a try square or carpenter's square. Adjust the clamps until the sash is square over all.

5. Clamp the first joint, on each side of the mortise and tenon joint, flat to the table. This keeps the driven pins from pushing wood out the exterior side of the sash.

6. Select a steel or stainless steel pin that is 3/8" shorter than the thickness of the sash. Pins should not have a point on the ends as they will split the wood when driven into the joint.

7. Cut the head off a finish nail that is slightly smaller than the diameter of the pin. Use this nail in a drill to create a pilot hole for the pin. Do not use a drill bit, which removes wood by cutting. The nail ploughs through the wood and the fibers can then squeeze back around the pin, holding the pin in place.

8. Drill two pilot holes through the interior face of the sash, through the tenon and just into the bottom side of the mortise. Angle each pilot hole at an opposing angle of about 7 degrees to each other.

9. Drive the two pins into the pilot holes and set them 1/8" below the surface with a nail set. After priming fill the pin holes with glazing putty.

10. Repeat the procedure above for each loose mortise and tenon joint on the sash.

11. Check to assure all mortise and tenon joints are tighten up and the sash is square.

Materials:
• Stainless steel pins
Hot dipped, galvanized exterior casing/finish nail
• Finish nail as drill bit
Quality of Results:

Best Work:
Joints are tight. The sash is square. The pins go through the body of the tenon and into the bottom side of the mortise, and do not come through the exterior face of the joint. Pins are set and holes filled with putty.

Inadequate Work:
Open gaps in the joints because some debris was not removed from the joint. Joints are still loose. Sash pins were installed from the exterior face. The sash is not square.


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