Needs Pictures: 0
Results 1 to 15 of 108
-
9th May 2018, 09:41 AM #1
Should I convert to keg Pocket Holes or stay with Mortise and Tenons on Deck Bench?
A special thanks to board administrators.
Don't know how but my pic selection has returned to multiple selections at once.
Many many thanks.
This Lutyens garden bench (with some expert help from a forum member here) was my first huge challenge.
And continues to be a huge challenge when dismantling and re-glueing.
It was build pretty much as I went along.
The tenons were cut with triton work station. 3mm at a time.
The mortise with a mortise jig (mortiser ?) fit to my drill press.
Not well. By me as a beginner.
Then each tenon edge was shaped by hand.
It was an excruciatingly long process.
Some of the tenons have disintegrated.
And kreg pocket hole jigs have become more popular and more accepted.
Over the years if we had a big party planned I've quickly applied glue to keep everything together just for the party.
This year I want to do it right.
Plan, plan and more planning.
The back is pretty much ready to be pulled apart easily as the glue seems to have failed from weather exposure.
The bottom will take a bit more effort.
I do want to modify the bottom to move the front bottom cross support up and back to make room for a broom like the later version.
And pretty much remove the bottom back cross support.
I want to cup the seat as in the later version as well.
I recall 1"/25.4mm deep no matter the width of the seat.
It's so much more comfortable.
I'd slant the back like the later version as well if I knew how.
I'm pretty sure I can dismantle all mortise and tenon by hand or with a couple blows with the rubber mallet.
The question is:
Should I stay with the really bad mortise and tenons?
Or perhaps fill the mortise (or replace the mortised boards) and cut the tenons off and use kreg pocket hole screws?
Or maybe replace the mortise and tenons with new mortise and tenon boards altogether?
Now that I've written that and read it back it sounds really strange in my head.
Any positive constructive suggestions would be greatly appreciated.
Thanks in advance.
IMG_9044.jpg IMG_9036.jpg IMG_9037.jpg IMG_9038.jpg IMG_9039.jpg IMG_9040.jpg IMG_9041.jpg IMG_9042.jpg IMG_9043.jpg IMG_9035.jpgThanks,
Barry G. Sumpter
May Yesterdays Tears Quench the Thirst for Tomorrows Revenge
-
9th May 2018 09:41 AM # ADSGoogle Adsense Advertisement
- Join Date
- Always
- Location
- Advertising world
- Posts
- Many
-
9th May 2018, 11:52 AM #2
Hi Barry
given the scale of what you are contemplating and your desire to incorporate a number of improvements, I suggest you bite the bullet and build a new version.
I have little faith in pocket screws holding for any length of time in weathered timber.regards from Alberta, Canada
ian
-
9th May 2018, 12:01 PM #3SENIOR MEMBER
- Join Date
- Jul 2014
- Location
- Brisbane
- Posts
- 952
So I'm not an expert and happy to be corrected by others but it seems like you have several issues. The glue layer seems quite thick, perhaps indicating that the mortise and tenon joints are not very tight, which would lead to water collecting in the mortises, your tenons starting to rot and then disintegrating. And the glue selection may not have been the best? Some of the members also seem to have shrunk quite a bit (second photo).
I wouldn't think pocket holes would be a long term fix by themselves, since you'll still have ill fitting joints and exposed to the elements, the pocket holes and screws will give way as well as water gets into the screw holes and repeats the story of the mortises and tenons. The other issue you'll face with pocket holes is that if the piece with the pocket hole doesn't seat properly against the piece being screwed into and you only have 1 screw at each end, it's going to spin.
I would suggest a longer term fix would be scraping off all of the old glue, using a wood hardener to remedy the rot in the tenons and mortises, then a gap filling glue (epoxy) that can bridge the hopefully small voids in the joinery and stand up to exterior use at the same. Where the tenons are completely broken off, you could use a pocket hole and screw then fill any gaps with epoxy. Might be messy. Or cut a dado into the stub where the tenon was and insert a new tenon.
At some point it might actually be easier remaking the whole bench I think.
-
9th May 2018, 04:37 PM #4
If the timber is sound, I would replace the tenons with loose tenon joinery. I would never go near screws for outdoors. If the timber is not sound, then as Ian suggested, rebuild the lot from scratch.
Regards from Perth
DerekVisit www.inthewoodshop.com for tutorials on constructing handtools, handtool reviews, and my trials and tribulations with furniture builds.
-
9th May 2018, 05:13 PM #5
Many thanks gents!
Much appreciated.
I plan on using 2 screws per join.
I've been using stainless steel screws in my undercover boxes.
Wouldn't the kreg stainless steel screws be ok for the outdoor pocket holes?
And in conjunction with Titebond III?
I don't mind scrapping off the old glue to clean up and then the loose tenon solution.
And this time I plan on putting all together in the work shop on the work table clamped properly etc.
hmmmm
oops never mind.
I just recalled the fine threaded stainless steel search.
which ended up as Kreg only for 33c each.
Frak!
https://www.carbatec.com.au/joinery-...-fine-ss-100pcThanks,
Barry G. Sumpter
May Yesterdays Tears Quench the Thirst for Tomorrows Revenge
-
9th May 2018, 06:06 PM #6GOLD MEMBER
- Join Date
- Apr 2014
- Location
- Little River
- Age
- 78
- Posts
- 1,207
Your biggest problem with any tenons that have come loose is that if the original glue was PVA then there will be a layer of PVA on the inside of both the mortise and tenon. This has to be totally removed as any new PVA will not stick to the old stuff. The alternative is to use epoxy which will stick and also fill any gaps left after the disassembly. Screws will only be a help during the glue going off and are not really suitable for something like chair construction as they tend to allow the timbers to crush and joints to move whenever the load changes.
My recommendation is to use lots of epoxy and clamps and to only use screws if you don't have clamps or they are unsuitable.
-
9th May 2018, 06:39 PM #7
One of the reasons you're having problems now is the poor M&T's allowed water in, which sat and caused deterioration.
As for using screws (pocket or otherwise), well...
...and this crushing/movement englarges the holes, which will let water in and...
So you'd still end up with similar problems further down the line.
- Andy Mc
-
9th May 2018, 08:17 PM #8
The other problem also is when you sand/scrape or clean up the weathered exterior you will loose about 2mm per side so on all the small sections there won't be a lot left for any screw to get a reasonable bite or support.
Resin in the joints with loose tenons is the go or new timber and rebuild, at least you know what has caused most of the existing problems and you have gained experience since building it so now you have the perfect opportunity to do a first class job and impress you know who and she will be super impressed.The person who never made a mistake never made anything
Cheers
Ray
-
9th May 2018, 08:44 PM #9Taking a break
- Join Date
- Aug 2008
- Location
- Melbourne
- Age
- 34
- Posts
- 6,127
Whatever you end up doing, make sure you keep it covered when it's not needed. It's clearly been left fully exposed to the elements and you'll end up right back where you are now in a few years if you don't protect it.
-
10th May 2018, 08:22 AM #10
Excellent advice gents.
Much appreciated.
Nixed on a new build.
I'm wondering if epoxy is expensive?
OK. Here's what I'm thinking.
Epoxy ( adhesive NOT resin ) as a gap filling glue between joints
Wood hardener
Loose tenons
wider mortise
remove joint glue by removing all existing tenons.
re-drill mortise wider and deeper to a standard size removing glue
making my own loose tenons to fit mortise properly
gluing using epoxy
Keep covered
sounds like a start
https://www.quora.com/What-is-the-di...d-epoxy-resins
https://www.artofmanliness.com/artic...iture-repairs/
https://www.carbatec.com.au/joinery-...de-237ml-brown
https://www.popularwoodworking.com/p...-tenon-joinery
Sketchup | 3D Warehouse | Woodworking Loose Tenon Mortising Jig
https://www.youtube.com/watch?v=zORuOdjasMoThanks,
Barry G. Sumpter
May Yesterdays Tears Quench the Thirst for Tomorrows Revenge
-
10th May 2018, 10:48 AM #11
Barry, to the above add fresh timber, and the old bench will be as good as new
Regards from Perth
DerekVisit www.inthewoodshop.com for tutorials on constructing handtools, handtool reviews, and my trials and tribulations with furniture builds.
-
10th May 2018, 11:20 AM #12
Oops I did mean to say epoxy in my previous post (not resin)
The person who never made a mistake never made anything
Cheers
Ray
-
10th May 2018, 01:44 PM #13
any specific brand of epoxy adhesive?
Thanks,
Barry G. Sumpter
May Yesterdays Tears Quench the Thirst for Tomorrows Revenge
-
10th May 2018, 01:53 PM #14Taking a break
- Join Date
- Aug 2008
- Location
- Melbourne
- Age
- 34
- Posts
- 6,127
-
10th May 2018, 02:15 PM #15
I was thinking about this a bit overnight. My MIL had some ancient outdoor furniture she utterly refused to throw out despite the fact it was completely RS.
Any repairs on the timber were almost a waste of time. Once the wood has lost its density it simply didn't hold things properly. It could certainly be repaired enough for a sit or five, but two years? No way.
Despite glueing and screws (chunky ones from Kreg) is really didn't hold together too well. One more summer and it was time for the tip.
For this bench, perhaps you could use big dowels, the biggest that will fit inside the timber... such as 20mm. Drill them deep (50mm) and epoxy them in, then drill right through the benches side and make it into a split wedged-tenon... use gobs of epoxy. The wedged tenon will completely stop any pull-out or movement.
I look forward to seeing how this goes... but I suspect it would be better to use the old seat parts as templates and make new bits!
A Grandfathers Axe
Similar Threads
-
Filling Pocket Holes
By kpphotos in forum FINISHINGReplies: 6Last Post: 6th August 2016, 12:35 AM -
What exactly is a 2 x 2 and what do you think of pocket holes?
By Gerry_K in forum WOODWORK - GENERALReplies: 13Last Post: 19th April 2015, 10:21 PM -
Mortise and tenons on cot
By wills in forum FURNITURE, JOINERY, CABINETMAKING - formerly BIG STUFFReplies: 3Last Post: 27th November 2010, 08:55 PM -
mortise & tenons, tenoning jigs
By woodhog in forum WOODWORK - GENERALReplies: 2Last Post: 16th November 2006, 02:05 PM -
plugs for pocket holes
By Kev Y. in forum WOODWORK - GENERALReplies: 8Last Post: 5th May 2005, 11:09 PM