Sometime this summer I have to deal with my garage.

Historically, it was extended at the front by about 4 feet. This
extension is slowly falling down and I could use the space on the drive,
so I'm proposing to demolish and go back to the original. Part of the
joy of living in a conservation area is that I have to await planning
permission, but I am assured by the conservation officer that this
shouldn't be a problem, as the proposal involves restoring the external
appearance of the original Victorian coach house. Part of this will be
to reinstate the same or similar doors.

The original hinge pins are still set in place in the brickwork,
although these are bigger than the current hinges, so dealing with that
will be a joy. (I bet they're not plumb either!)

The current/original doors are heavy arched ledged and braced affairs
clad in thick tongue and groove boards. I could transplant these or
(more practically) make a reasonable facsimilie that might be lighter
though still secure. One advantage would be that the new pair would be
fitted before demolition, making the job simpler.

Anyway...I was thinking (yes I know - bad idea)that one way to make the
new doors would be to take a sheet of 12mm ply and route grooves along
it (to reproduce the board effect once painted), cut to shape, and mount
on a ledge and brace frame. This would seem likely to provide a more
dimensionally robust outcome than boarding.

I've never seen this done, which makes me wonder if there's a reason not
to do it that way that I haven't thought of.

Any thoughts chaps?

On 07/05/2015 08:59, GMM wrote:
Sometime this summer I have to deal with my garage.

Historically, it was extended at the front by about 4 feet. This
extension is slowly falling down and I could use the space on the drive,
so I'm proposing to demolish and go back to the original. Part of the
joy of living in a conservation area is that I have to await planning
permission, but I am assured by the conservation officer that this
shouldn't be a problem, as the proposal involves restoring the external
appearance of the original Victorian coach house. Part of this will be
to reinstate the same or similar doors.

The original hinge pins are still set in place in the brickwork,
although these are bigger than the current hinges, so dealing with that
will be a joy. (I bet they're not plumb either!)

Measure them and visit an architectural ironmonger. Rare though they are
these days, they can usually match anything you need.

The current/original doors are heavy arched ledged and braced affairs
clad in thick tongue and groove boards. I could transplant these or
(more practically) make a reasonable facsimilie that might be lighter
though still secure. One advantage would be that the new pair would be
fitted before demolition, making the job simpler.

Anyway...I was thinking (yes I know - bad idea)that one way to make the
new doors would be to take a sheet of 12mm ply and route grooves along
it (to reproduce the board effect once painted), cut to shape, and mount
on a ledge and brace frame. This would seem likely to provide a more
dimensionally robust outcome than boarding.

I've never seen this done, which makes me wonder if there's a reason not
to do it that way that I haven't thought of.

I don't see a problem in principle, provided the conservation officer
doesn't insist upon T&G, although I suspect 12mm ply will be a bit thin
for the job. I would use at least 15mm ply and possibly thicker,
depending upon the door size.


--
Colin Bignell

On Thursday, May 7, 2015 at 10:30:04 AM UTC+1, Nightjar wrote:
On 07/05/2015 08:59, GMM wrote:
Sometime this summer I have to deal with my garage.

Historically, it was extended at the front by about 4 feet. This
extension is slowly falling down and I could use the space on the drive,
so I'm proposing to demolish and go back to the original. Part of the
joy of living in a conservation area is that I have to await planning
permission, but I am assured by the conservation officer that this
shouldn't be a problem, as the proposal involves restoring the external
appearance of the original Victorian coach house. Part of this will be
to reinstate the same or similar doors.

The original hinge pins are still set in place in the brickwork,
although these are bigger than the current hinges, so dealing with that
will be a joy. (I bet they're not plumb either!)

Measure them and visit an architectural ironmonger. Rare though they are
these days, they can usually match anything you need.

The current/original doors are heavy arched ledged and braced affairs
clad in thick tongue and groove boards. I could transplant these or
(more practically) make a reasonable facsimilie that might be lighter
though still secure. One advantage would be that the new pair would be
fitted before demolition, making the job simpler.

Anyway...I was thinking (yes I know - bad idea)that one way to make the
new doors would be to take a sheet of 12mm ply and route grooves along
it (to reproduce the board effect once painted), cut to shape, and mount
on a ledge and brace frame. This would seem likely to provide a more
dimensionally robust outcome than boarding.

I've never seen this done, which makes me wonder if there's a reason not
to do it that way that I haven't thought of.

I don't see a problem in principle, provided the conservation officer
doesn't insist upon T&G, although I suspect 12mm ply will be a bit thin
for the job. I would use at least 15mm ply and possibly thicker,
depending upon the door size.


--
Colin Bignell

Wouildn't do that. 12mm is too thin and anyway routing grooves will expose the laminations in the ply. You also would need to use LLoyds approved marine ply. Exterior grade and standard marine ply wouldn't cut the mustard I.M.H.O.

On 07/05/2015 10:59, fred wrote:



Anyway...I was thinking (yes I know - bad idea)that one way to make the
new doors would be to take a sheet of 12mm ply and route grooves along
it (to reproduce the board effect once painted), cut to shape, and mount
on a ledge and brace frame. This would seem likely to provide a more
dimensionally robust outcome than boarding.



Wouildn't do that. 12mm is too thin and anyway routing grooves will expose the laminations in the ply. You also would need to use LLoyds approved marine ply. Exterior grade and standard marine ply wouldn't cut the mustard I.M.H.O.

+1

You definitely need to keep the edges of plywood dry, 'cos it
de-laminates if water gets in. By cutting grooves you'd effectively be
creating a lot more "edges". Besides which, you'd be exposing the inner
layers which are probably made of inferior wood compared with the
outside layers.
--
Cheers,
Roger
____________
Please reply to Newsgroup. Whilst email address is valid, it is seldom
checked.

On 07/05/2015 10:59, fred wrote:
....
Wouildn't do that. 12mm is too thin and anyway routing grooves will expose the laminations in the ply. You also would need to use LLoyds approved marine ply. Exterior grade and standard marine ply wouldn't cut the mustard I.M.H.O.


I've used WPB ply for outdoor signs that have lasted for many years. The
important bit, as with many woods, is to ensure that it is very well
painted, particularly around the edges.

--
Colin Bignell

On Thursday, May 7, 2015 at 2:54:03 PM UTC+1, Nightjar wrote:
On 07/05/2015 10:59, fred wrote:
...
Wouildn't do that. 12mm is too thin and anyway routing grooves will expose the laminations in the ply. You also would need to use LLoyds approved marine ply. Exterior grade and standard marine ply wouldn't cut the mustard I.M.H.O.


I've used WPB ply for outdoor signs that have lasted for many years. The
important bit, as with many woods, is to ensure that it is very well
painted, particularly around the edges.

--
Colin Bignell

Our signwriter refuses to use exterior grade ply for his signs after numerous complaints about de-lamination. This despite all having full hardwood frames. And certainly I have seen evidence of this in shop signs around the country.You have been exceptionally lucky. Its the voids that cause the problem. Moisture gets in and nature has her way. Painting will not prevent this as the culprit is internal. A friend built a small punt two years ago using exterior grade ply, against all advice. He only had it in and out of the water a few times when the trouble started.

Not worth the risk

On 07/05/2015 10:29, Nightjar "cpb"@ wrote:
On 07/05/2015 08:59, GMM wrote:
Sometime this summer I have to deal with my garage.

Historically, it was extended at the front by about 4 feet. This
extension is slowly falling down and I could use the space on the drive,
so I'm proposing to demolish and go back to the original. Part of the
joy of living in a conservation area is that I have to await planning
permission, but I am assured by the conservation officer that this
shouldn't be a problem, as the proposal involves restoring the external
appearance of the original Victorian coach house. Part of this will be
to reinstate the same or similar doors.

The original hinge pins are still set in place in the brickwork,
although these are bigger than the current hinges, so dealing with that
will be a joy. (I bet they're not plumb either!)

Measure them and visit an architectural ironmonger. Rare though they are
these days, they can usually match anything you need.

I'm sure there must be one around somewhere - it's just a matter of
tracking them down. The pins are 22mm in diameter, so I'm guessing
that's 7/8 in old money.
My next door neighbour made his own from some field gate hinges. He's a
retired mechanical engineer. so should be good at that sort of thing.
I'm wondering whether a bottle of wine might induce him to repeat the
exercise.....


The current/original doors are heavy arched ledged and braced affairs
clad in thick tongue and groove boards. I could transplant these or
(more practically) make a reasonable facsimilie that might be lighter
though still secure. One advantage would be that the new pair would be
fitted before demolition, making the job simpler.

Anyway...I was thinking (yes I know - bad idea)that one way to make the
new doors would be to take a sheet of 12mm ply and route grooves along
it (to reproduce the board effect once painted), cut to shape, and mount
on a ledge and brace frame. This would seem likely to provide a more
dimensionally robust outcome than boarding.

I've never seen this done, which makes me wonder if there's a reason not
to do it that way that I haven't thought of.

I don't see a problem in principle, provided the conservation officer
doesn't insist upon T&G, although I suspect 12mm ply will be a bit thin
for the job. I would use at least 15mm ply and possibly thicker,
depending upon the door size.


My experience of the conservation officer is that providing the proposal
looks OK ('replace existing doors or to a similar pattern if not fit for
purpose') nothing gets checked unless someone whinges, so appearance
from the street is everything. The originals are (IMO) unnecessarily
effin' heavy.

Thicker is always feasible: These are pretty big but I was thinking the
structural strength would be given by the L&B frames, with the ply
acting as a skin that kept everything in place and covered it all. I
was sort of thinking that an inner skin of celotex might be a good idea,
maybe sandwiched with an inner ply layer.

Clearly a good covering of paint (and maybe something to seal it etc
first) is essential, but I see that as happening before hanging, when
it's easier to do a thorough job. These will be quite well sheltered,
as they sit in a recess, but vapour will always be around of course.

On 07/05/2015 16:31, fred wrote:
On Thursday, May 7, 2015 at 2:54:03 PM UTC+1, Nightjar wrote:
On 07/05/2015 10:59, fred wrote:
...
Wouildn't do that. 12mm is too thin and anyway routing grooves will expose the laminations in the ply. You also would need to use LLoyds approved marine ply. Exterior grade and standard marine ply wouldn't cut the mustard I.M.H.O.


I've used WPB ply for outdoor signs that have lasted for many years. The
important bit, as with many woods, is to ensure that it is very well
painted, particularly around the edges.

--
Colin Bignell

Our signwriter refuses to use exterior grade ply for his signs after numerous complaints about de-lamination. This despite all having full hardwood frames.

Probably a mistake. It prevents you inspecting the edges and making sure
they remain well sealed.

And certainly I have seen evidence of this in shop signs around the country.You have been exceptionally lucky.

Perhaps I am just rather better at making sure the paint properly seals
the entire surface and maintaining it that way.

Its the voids that cause the problem. Moisture gets in and nature has her way. Painting will not prevent this as the culprit is internal.

It is only internal if the moisture gets in and paint can prevent that,
but it needs to be properly maintained for that to happen.

A friend built a small punt two years ago using exterior grade ply, against all advice. He only had it in and out of the water a few times when the trouble started.

Entirely different situation. A punt is subject to immersion in water
and inevitably gets knocks and scrapes that make it impossible to seal
the surface satisfactorily.


--
Colin Bignell

On 07/05/2015 20:19, GMM wrote:
On 07/05/2015 10:29, Nightjar "cpb"@ wrote:
....
Measure them and visit an architectural ironmonger. Rare though they are
these days, they can usually match anything you need.

I'm sure there must be one around somewhere - it's just a matter of
tracking them down. The pins are 22mm in diameter, so I'm guessing
that's 7/8 in old money.
My next door neighbour made his own from some field gate hinges. He's a
retired mechanical engineer. so should be good at that sort of thing.
I'm wondering whether a bottle of wine might induce him to repeat the
exercise.....

Similar in size to the pins on my double gate and I bought those off the
shelf. However, if you can get them made it is probably even better.

.....
I don't see a problem in principle, provided the conservation officer
doesn't insist upon T&G, although I suspect 12mm ply will be a bit thin
for the job. I would use at least 15mm ply and possibly thicker,
depending upon the door size.


My experience of the conservation officer is that providing the proposal
looks OK ('replace existing doors or to a similar pattern if not fit for
purpose') nothing gets checked unless someone whinges, so appearance
from the street is everything. The originals are (IMO) unnecessarily
effin' heavy.

Thicker is always feasible: These are pretty big but I was thinking the
structural strength would be given by the L&B frames, with the ply
acting as a skin that kept everything in place and covered it all. I
was sort of thinking that an inner skin of celotex might be a good idea,
maybe sandwiched with an inner ply layer.

I was going by the thickness of the planks on my gates, which are 15mm
thick. A skin on each side of the frame would obviously be stronger, but
I would still go for at least 15mm on the outside, if only for security.
You might want to make the inner skin removable, so that you can
occasionally inspect the frame for rot. IME, that is what usually fails
first on gates.

Clearly a good covering of paint (and maybe something to seal it etc
first) is essential, but I see that as happening before hanging, when
it's easier to do a thorough job.

That is what I've done with new side gates I have bought. It allows me
to be sure that the bottom edge is very well sealed.

These will be quite well sheltered,
as they sit in a recess, but vapour will always be around of course.


--
Colin Bignell

On 07/05/2015 16:31, fred wrote:
A friend built a small punt two years ago using exterior grade ply, against all advice. He only had it in and out of the water a few times when the trouble started.

My limited experience is that the quality of marine ply isn't what it
used to be either.

Andy

On Thursday, May 7, 2015 at 9:55:54 PM UTC+1, Vir Campestris wrote:
On 07/05/2015 16:31, fred wrote:
A friend built a small punt two years ago using exterior grade ply, against all advice. He only had it in and out of the water a few times when the trouble started.

My limited experience is that the quality of marine ply isn't what it
used to be either.

Andy

Too true. There was a lot of cheap Chinese ply on the market a while back. Like most things in life with ply you get what you pay for and there is nothing in this world someone can't make cheaper and worse.Caveat emptor.

On Thursday, May 7, 2015 at 8:43:57 PM UTC+1, Nightjar wrote:
On 07/05/2015 16:31, fred wrote:
On Thursday, May 7, 2015 at 2:54:03 PM UTC+1, Nightjar wrote:
On 07/05/2015 10:59, fred wrote:
...
Wouildn't do that. 12mm is too thin and anyway routing grooves will expose the laminations in the ply. You also would need to use LLoyds approved marine ply. Exterior grade and standard marine ply wouldn't cut the mustard I.M.H.O.


I've used WPB ply for outdoor signs that have lasted for many years. The
important bit, as with many woods, is to ensure that it is very well
painted, particularly around the edges.

--
Colin Bignell

Our signwriter refuses to use exterior grade ply for his signs after numerous complaints about de-lamination. This despite all having full hardwood frames.

Probably a mistake. It prevents you inspecting the edges and making sure
they remain well sealed.


Nonsense. The man is a professional sign writer who we have been using for over 20 years. He knows well how to protect the edges of plywood and will tell you that ply does bot take paint very well along the edges due to the varying qualities of the veneers used and the intermediate layers of glue all of which absorb paint at a different rate leading to those tell tale poor edges. Proper protection of the edges of ply requires a solid wood lipping..Besides if plywood does take in moisture along its edges it is along these edges it will de-laminate giving a nice frilly appearance, not in the centre of sheets. I've no idea how many signa you made, what size they were and how they were mounted but I'll guarantee this man makes more in a week than you make in a lifetime.

And certainly I have seen evidence of this in shop signs around the country.You have been exceptionally lucky.

Perhaps I am just rather better at making sure the paint properly seals
the entire surface and maintaining it that way.

Its the voids that cause the problem. Moisture gets in and nature has her way. Painting will not prevent this as the culprit is internal.

It is only internal if the moisture gets in and paint can prevent that,
but it needs to be properly maintained for that to happen.


No. The internal voids will already have moisture present sue to the varying moisture content of the veneers employed. After that varying atmospheric humidity can cause the problems.All the paint in the world will not avoid this. One of the essential features of marine ply is the complete absence of these voids.

A friend built a small punt two years ago using exterior grade ply, against all advice. He only had it in and out of the water a few times when the trouble started.

Entirely different situation. A punt is subject to immersion in water
and inevitably gets knocks and scrapes that make it impossible to seal
the surface satisfactorily.

Well actually the punt was not immersed in water. It floated, and only for a few short periods of time as the kids soon got bored very quickly. After that it lay face down on timber supports on his patio and was subject to rain only. When I saw it it still looked immaculate apart from the de-laminations. He finished it with Epifanes varnish, to the recommended procedure of 7 coats. Being a dinghy racer he is well familiar with finishing boats. He also used West System epoxy on all adjoining surfaces. Despite all this effort he still had problems.

Possibly your signs were small and did not contain any voids but the o.p. using it to make a garage door is a different cup of tea entirely.

Personally I prefer to take the view of the professionals in these matters. I wouldn't take the risk of using it as the o.p. suggested.

On 08/05/2015 08:20, fred wrote:
On Thursday, May 7, 2015 at 8:43:57 PM UTC+1, Nightjar wrote:
On 07/05/2015 16:31, fred wrote:
On Thursday, May 7, 2015 at 2:54:03 PM UTC+1, Nightjar wrote:
On 07/05/2015 10:59, fred wrote:
...
Wouildn't do that. 12mm is too thin and anyway routing grooves will expose the laminations in the ply. You also would need to use LLoyds approved marine ply. Exterior grade and standard marine ply wouldn't cut the mustard I.M.H.O.


I've used WPB ply for outdoor signs that have lasted for many years. The
important bit, as with many woods, is to ensure that it is very well
painted, particularly around the edges.

--
Colin Bignell

Our signwriter refuses to use exterior grade ply for his signs after numerous complaints about de-lamination. This despite all having full hardwood frames.

Probably a mistake. It prevents you inspecting the edges and making sure
they remain well sealed.


Nonsense. The man is a professional sign writer who we have been using for over 20 years. He knows well how to protect the edges of plywood and will tell you that ply does bot take paint very well along the edges due to the varying qualities of the veneers used and the intermediate layers of glue all of which absorb paint at a different rate leading to those tell tale poor edges. Proper protection of the edges of ply requires a solid wood lipping.Besides if plywood does take in moisture along its edges it is along these edges it will de-laminate giving a nice frilly appearance, not in the centre of sheets. I've no idea how many signa you made, what size they were and how they were mounted but I'll guarantee this man makes more in a week than you make in a lifetime....

I have little doubt he does. I am also fairly sure he wouldn't make a
profit if he spent as much time as I did on preparing and protecting the
signs. You can get a good finish on the edges of ply, but it takes a lot
of care, many coats of paint and a long time. That is the advantage of
DIY over the professional - you don't need to justify the cost of taking
your time over a job.


--
Colin Bignell

On Friday, May 8, 2015 at 9:07:04 AM UTC+1, Nightjar wrote:
On 08/05/2015 08:20, fred wrote:
On Thursday, May 7, 2015 at 8:43:57 PM UTC+1, Nightjar wrote:
On 07/05/2015 16:31, fred wrote:
On Thursday, May 7, 2015 at 2:54:03 PM UTC+1, Nightjar wrote:
On 07/05/2015 10:59, fred wrote:
...
Wouildn't do that. 12mm is too thin and anyway routing grooves will expose the laminations in the ply. You also would need to use LLoyds approved marine ply. Exterior grade and standard marine ply wouldn't cut the mustard I.M.H.O.


I've used WPB ply for outdoor signs that have lasted for many years. The
important bit, as with many woods, is to ensure that it is very well
painted, particularly around the edges.

--
Colin Bignell

Our signwriter refuses to use exterior grade ply for his signs after numerous complaints about de-lamination. This despite all having full hardwood frames.

Probably a mistake. It prevents you inspecting the edges and making sure
they remain well sealed.


Nonsense. The man is a professional sign writer who we have been using for over 20 years. He knows well how to protect the edges of plywood and will tell you that ply does bot take paint very well along the edges due to the varying qualities of the veneers used and the intermediate layers of glue all of which absorb paint at a different rate leading to those tell tale poor edges. Proper protection of the edges of ply requires a solid wood lipping.Besides if plywood does take in moisture along its edges it is along these edges it will de-laminate giving a nice frilly appearance, not in the centre of sheets. I've no idea how many signa you made, what size they were and how they were mounted but I'll guarantee this man makes more in a week than you make in a lifetime....

I have little doubt he does. I am also fairly sure he wouldn't make a
profit if he spent as much time as I did on preparing and protecting the
signs. You can get a good finish on the edges of ply, but it takes a lot
of care, many coats of paint and a long time. That is the advantage of
DIY over the professional - you don't need to justify the cost of taking
your time over a job.


--
Colin Bignell

More nonsense. You can't teach a man his job. The accepted method of protecting the edge of plywood is with a hardwood edge. Lashing on paint is amateurish and only faffing around. And painting the edges would only stop moisture entering along the edges where, if it does, the ply de-laminates along the edge. It will do nothing to stop voids within the ply from causing the characteristic bubbles and splits.

On 08/05/2015 09:56, fred wrote:
....
More nonsense. You can't teach a man his job.

His job is to make a product that his customers want, at a price they
are willing to pay, which has very little to do with what I was talking
about.

The accepted method of protecting the edge of plywood is with a hardwood edge.

I must tell that to the joiner who made a very serviceable pair of
plywood doors for an outdoor meter cupboard on one of my factory units
and didn't feel the need.

Lashing on paint is amateurish and only faffing around....

It was rather more scientific than simply lashing on paint and the
bottom line is that it worked.


--
Colin Bignell

On Friday, May 8, 2015 at 2:51:26 PM UTC+1, Nightjar wrote:
On 08/05/2015 09:56, fred wrote:
...
More nonsense. You can't teach a man his job.

His job is to make a product that his customers want, at a price they
are willing to pay, which has very little to do with what I was talking
about

On the contrary his job is to produce satisfactory work. The fact that he felt he couldn't do this with exterior grade ply says it all.

He is a pro, an expert if you like. Someone worth listening to. Someone long enough at the job to have loads of experience. Much more than an amateur who has made a few signs and now believes that HE is the expert. Get real

The accepted method of protecting the edge of plywood is with a hardwood edge.

I must tell that to the joiner who made a very serviceable pair of
plywood doors for an outdoor meter cupboard on one of my factory units
and didn't feel the need.

Yes that would be an excellent idea. Hopefully he will appreciate learning how to do it correctly.

Lashing on paint is amateurish and only faffing around....

It was rather more scientific than simply lashing on paint and the
bottom line is that it worked.


It worked? Says you.

Scientific painting ? Wow. To be honest I'm intrigued to know how you applied numerous coats of paint to the edge of a plywood sign without it dripping all over the face of the sign itself. Though I suppose you'll now tell us you painted the sign itself numerous times. What a lot of work when you could just have used the proper ply in the first place or used a waterproof filler to seal the edge of the play instead of having to repaint it numerous time which I still doubt would seal it effectively anyway.

And how did you fix this sign? Bracket? Screws ? Whatever, you must have had to drill holes, the achilles heel of any ply. Wait though. You glued it up. Right ?

So how many signs did you actually do like this ? And how many weeks did it take?

--
Colin Bignell

fred wrote:
On Friday, May 8, 2015 at 2:51:26 PM UTC+1, Nightjar wrote:
On 08/05/2015 09:56, fred wrote:
...
More nonsense. You can't teach a man his job.

His job is to make a product that his customers want, at a price they
are willing to pay, which has very little to do with what I was talking
about

On the contrary his job is to produce satisfactory work. The fact that he felt he couldn't do this with exterior grade ply says it all.

He is a pro, an expert if you like. Someone worth listening to. Someone long enough at the job to have loads of experience. Much more than an amateur who has made a few signs and now believes that HE is the expert. Get real

The accepted method of protecting the edge of plywood is with a hardwood edge.

I must tell that to the joiner who made a very serviceable pair of
plywood doors for an outdoor meter cupboard on one of my factory units
and didn't feel the need.

Yes that would be an excellent idea. Hopefully he will appreciate learning how to do it correctly.

Lashing on paint is amateurish and only faffing around....

It was rather more scientific than simply lashing on paint and the
bottom line is that it worked.


It worked? Says you.

Scientific painting ? Wow. To be honest I'm intrigued to know how you applied numerous coats of paint to the edge of a plywood sign without it dripping all over the face of the sign itself. Though I suppose you'll now tell us you painted the sign itself numerous times. What a lot of work when you could just have used the proper ply in the first place or used a waterproof filler to seal the edge of the play instead of having to repaint it numerous time which I still doubt would seal it effectively anyway.

And how did you fix this sign? Bracket? Screws ? Whatever, you must have had to drill holes, the achilles heel of any ply. Wait though. You glued it up. Right ?

So how many signs did you actually do like this ? And how many weeks did it take?

--
Colin Bignell


My experience of wbp ply recently is that much of it is very poorly
laminated, with lots of voids and it crinkles very rapidly if left out
in the rain. I would not use it for doors unless it was a known well
sourced marine ply product.

On 08/05/2015 22:52, fred wrote:
On Friday, May 8, 2015 at 2:51:26 PM UTC+1, Nightjar wrote:
On 08/05/2015 09:56, fred wrote:
...
More nonsense. You can't teach a man his job.

His job is to make a product that his customers want, at a price they
are willing to pay, which has very little to do with what I was talking
about

On the contrary his job is to produce satisfactory work. The fact that he felt he couldn't do this with exterior grade ply says it all.

What it says is that he didn't think he could do it at an acceptable
price using exterior grade ply.

He is a pro, an expert if you like. Someone worth listening to. Someone long enough at the job to have loads of experience....

Good for him. IME, it also means that he will have found the most
economic way to do a job, but that does not mean it is the only way to
do it.

The accepted method of protecting the edge of plywood is with a hardwood edge.

I must tell that to the joiner who made a very serviceable pair of
plywood doors for an outdoor meter cupboard on one of my factory units
and didn't feel the need.

Yes that would be an excellent idea. Hopefully he will appreciate learning how to do it correctly.

So, your professional is right, but mine must be wrong if he did it
another way?


Lashing on paint is amateurish and only faffing around....

It was rather more scientific than simply lashing on paint and the
bottom line is that it worked.


It worked? Says you.

Scientific painting ? Wow. To be honest I'm intrigued to know how you applied numerous coats of paint to the edge of a plywood sign without it dripping all over the face of the sign itself. Though I suppose you'll now tell us you painted the sign itself numerous times. What a lot of work when you could just have used the proper ply in the first place or used a waterproof filler to seal the edge of the play instead of having to repaint it numerous time which I still doubt would seal it effectively anyway.

I didn't have a choice of material; I worked with what I was given. If
you really want to know the process, which I rather doubt as you have
obviously already made your mind up, it was:

Shape the signs and drill any necessary fixing holes.
Fill and smooth all edges, ensuring all corners are well rounded.
Lay flat and apply one coat of wood preservative, working it well into
the edges.
When dry, turn over and apply second coat of preservative, again working
it well into the edges.
About a week later, apply one coat of primer, ensuring all edges were
covered.
When dry, turn over and repeat primer on second side, again covering the
edges.
When dry, apply first coat of undercoat to front and edges.
When dry, turn over, apply undercoat to back and edges.
Lightly sand
Repeat last three steps for second layer of undercoat.
Repeat for first top coat.
Repeat for second top coat, without the sanding.
Finally, paint the signs themselves.

As you may note, the edges had twice as many layers of paint as the faces.

And how did you fix this sign? Bracket? Screws ? Whatever, you must have had to drill holes, the achilles heel of any ply.

Bolted through the previously drilled and painted holes to steel
brackets on water barrel, which had also been painted with primer, two
undercoats and two top coats. The tops of the barrel were sealed with
specially made dipped PVC caps.

So how many signs did you actually do like this ?

It was all the signs for the residential estate I lived on at the time,
which is why I didn't have a choice of material - one of the other
residents supplied it FOC, while another supplied the paint. It would
have been three large signs at the entrance, plus road signs at one
crossroad and three T-junctions, plus a few other ancillary signs,
probably about 20 in all. I also did street name signs and waiting
restriction signs in self-coloured GRP and painted road markings at
every junction.

And how many weeks did it take?

I think it was more like months. as I said before, the advantage of DIY
is that you don't have to account for the time taken.


--
Colin Bignell

On Sunday, May 10, 2015 at 9:14:42 PM UTC+1, Nightjar wrote:
On 08/05/2015 22:52, fred wrote:
On Friday, May 8, 2015 at 2:51:26 PM UTC+1, Nightjar wrote:
On 08/05/2015 09:56, fred wrote:
...
More nonsense. You can't teach a man his job.

His job is to make a product that his customers want, at a price they
are willing to pay, which has very little to do with what I was talking
about

On the contrary his job is to produce satisfactory work. The fact that he felt he couldn't do this with exterior grade ply says it all.

What it says is that he didn't think he could do it at an acceptable
price using exterior grade ply.

You have a strange concept of business practices. Why on earth would he use an inferior product and risk upsetting his customer. He uses a more expensive product in an effort to offer best service rather than risk his reputation.
He is a pro, an expert if you like. Someone worth listening to. Someone long enough at the job to have loads of experience....

Good for him. IME, it also means that he will have found the most
economic way to do a job, but that does not mean it is the only way to
do it.

Again you grasp of business economics is very strange. The man uses the right product for the job which is what his customers require. They depend on his experience to receive a satisfactory job

No one said his method was the only way to do it. In fact the majority of his work is done with aluminium or acrylic sheet. The right product for the job not some make do and mend effort. Following your logic he should have used cardboard and clothed in it apoxy.

The accepted method of protecting the edge of plywood is with a hardwood edge.

I must tell that to the joiner who made a very serviceable pair of
plywood doors for an outdoor meter cupboard on one of my factory units
and didn't feel the need.

And did he use your fabulous finishing methods ?

If you found it satisfactory then thats o/k. It doesn't detract from the fact that the accepted method of finishing ply for exterior or even interior use is to using some type of edging. Yes its more expensive to do the job right but then perhaps your joiner knows his customer's primary requirements..

At the very minimum plywood requires some type of protection along its vulnerable edges. Be it lipping or epoxy filler it needs something.

Yes that would be an excellent idea. Hopefully he will appreciate learning how to do it correctly.

So, your professional is right, but mine must be wrong if he did it
another way?

No. That's not what I said. He could do it with hardboard if you wished. There's no right or wrong way. What there is is best accepted practice. There are loads of handymen out there happy to offer a shoddy finish at a cheap price and loads of people to whom price is the ultimate parameter.
Lashing on paint is amateurish and only faffing around....

It was rather more scientific than simply lashing on paint and the
bottom line is that it worked.


It worked? Says you.

Scientific painting ? Wow. To be honest I'm intrigued to know how you applied numerous coats of paint to the edge of a plywood sign without it dripping all over the face of the sign itself. Though I suppose you'll now tell us you painted the sign itself numerous times. What a lot of work when you could just have used the proper ply in the first place or used a waterproof filler to seal the edge of the play instead of having to repaint it numerous time which I still doubt would seal it effectively anyway.

I didn't have a choice of material; I worked with what I was given. If
you really want to know the process, which I rather doubt as you have
obviously already made your mind up, it was:

Shape the signs and drill any necessary fixing holes.
Fill and smooth all edges, ensuring all corners are well rounded.

Ahhh. Now we are filling the edges. So it isn't just a lashing on of paint.

And tell me di you not come across ANY voids in your cut edges ?

Lay flat and apply one coat of wood preservative, working it well into
the edges.
When dry, turn over and apply second coat of preservative, again working
it well into the edges.
About a week later, apply one coat of primer, ensuring all edges were
covered.
When dry, turn over and repeat primer on second side, again covering the
edges.
When dry, apply first coat of undercoat to front and edges.
When dry, turn over, apply undercoat to back and edges.
Lightly sand
Repeat last three steps for second layer of undercoat.
Repeat for first top coat.
Repeat for second top coat, without the sanding.
Finally, paint the signs themselves.

As you may note, the edges had twice as many layers of paint as the faces..

Doesn't make a blind bit of difference. When painting the edges of ply you are effectively painting end grain interspersed with resin glue. These layers react differently to atmospheric conditions causing them to move minutely but enough to allow the ingress of water. The inevitable result is a break down of the painted surface and the characteristic parallel cracks that can be observed later



And how did you fix this sign? Bracket? Screws ? Whatever, you must have had to drill holes, the achilles heel of any ply.

Bolted through the previously drilled and painted holes to steel
brackets on water barrel, which had also been painted with primer, two
undercoats and two top coats. The tops of the barrel were sealed with
specially made dipped PVC caps.

So how many signs did you actually do like this ?

It was all the signs for the residential estate I lived on at the time,
which is why I didn't have a choice of material - one of the other
residents supplied it FOC, while another supplied the paint. It would
have been three large signs at the entrance, plus road signs at one
crossroad and three T-junctions, plus a few other ancillary signs,
probably about 20 in all. I also did street name signs and waiting
restriction signs in self-coloured GRP and painted road markings at
every junction.

And how many weeks did it take?

I think it was more like months. as I said before, the advantage of DIY
is that you don't have to account for the time taken.

Laugh, I nearly cried. I left the door open and you walked right in. I had a little bet that you would come back with some fairy tale about the fabulous finish you used and the enormous quantity of signs you made,and you just couldn't resist, though the free materials was a nice touch.

The o.p's query was to the suitability of using 12mm ply for his new doors and grooving it to simulate t and g.

I offered the advice that he avoid exterior grade ply as IME it would not endure and also that cutting grooves in any ply was not a good idea.

You expressed no concern about cutting grooves in play and extolled the virtues of exterior grade ply. Now it appears that you spent hours faffing about with FREE paint and FREE ply. Funny I didn't see you pointing out these two very pertinent facts to the o.p.

All this concern you are now showing about the edges of the ply demonstrates your ignorance of the real problem, voids within the ply itself which cause the typical bubbles and cracks on the surface of the material exposed to the elements. Doesn't matter how much paint you apply. The problem is internal and will always win through. The ancient Greeks used wooden wedges to crack out rocks by the simple expedient of hammering them in to cracks and then soaking them with water. The same principle applies to the voids in ply. Because of the manufacturing method and the materials used moisture laden air is trapped within the layers of veneer where there are voids. Thats where the problems start. That's why best quality marine ply is guaranteed void free and why it is more expensive than wbp.

But have it your way. They're all out of step except my Johnny.
--
Colin Bignell

On 11/05/2015 09:04, fred wrote:
....
You have a strange concept of business practices. Why on earth would he use an inferior product and risk upsetting his customer. He uses a more expensive product in an effort to offer best service rather than risk his reputation.

The basic principle of business is to give your customer what they want
at a price they are willing to pay, while making the greatest profit
from doing so. Materials are usually a lot cheaper than labour so, for a
professional, using more expensive materials will often make more sense
than taking extra time and effort to get a cheaper material to do the
job. For the DIYer, the opposite may well be true.

....
Ahhh. Now we are filling the edges. So it isn't just a lashing on of paint.

That was your choice of phrase, not mine.

And tell me di you not come across ANY voids in your cut edges ?

It was the best part of half a century ago and I don't recall the
details, but I would have filled them if I had.

.....
Laugh, I nearly cried. I left the door open and you walked right in. I had a little bet that you would come back with some fairy tale about the fabulous finish you used and the enormous quantity of signs you made,and you just couldn't resist, though the free materials was a nice touch.

No 'nice touch'. Like any of my posts, the simple truth. I made a number
of signs for a residential estate I lived on. I made them from WPB and
they were still there, doing their job, when I moved away several years
later.

....
Now it appears that you spent hours faffing about with FREE paint and FREE ply. Funny I didn't see you pointing out these two very pertinent facts to the o.p....

I would take it as read that any DIYer would understand that making sure
that something is very well painted will involve hours of faffing about.
The fact that I didn't mention I was using free materials is totally
irrelevant.

Essentially, this comes down to you getting your knickers in a twist
because I dared to disagree with you.

--
Colin Bignell

On Monday, May 11, 2015 at 5:43:12 PM UTC+1, Nightjar wrote:
On 11/05/2015 09:04, fred wrote:
...
You have a strange concept of business practices. Why on earth would he use an inferior product and risk upsetting his customer. He uses a more expensive product in an effort to offer best service rather than risk his reputation.

The basic principle of business is to give your customer what they want
at a price they are willing to pay, while making the greatest profit
from doing so. Materials are usually a lot cheaper than labour so, for a
professional, using more expensive materials will often make more sense
than taking extra time and effort to get a cheaper material to do the
job. For the DIYer, the opposite may well be true.

For this DIYer the opposite most certainly is not true. I value my time too much for that, On the basis that I am saving others labour costs I will use the best material I think suit the job. No DIYer worth his salt ois going to use cheap materials unless he wants a cheap job.

...
Ahhh. Now we are filling the edges. So it isn't just a lashing on of paint.

That was your choice of phrase, not mine.

The choice of the phrase is irrelevant to the poing I am making'

This is the FIRST time you have made any mention of filling anything, a most essential step when using ply.

And tell me di you not come across ANY voids in your cut edges ?

It was the best part of half a century ago and I don't recall the
details, but I would have filled them if I had.


What ? You don't recall the details? You've just given precise details of the alleged process but you now appear to have left out the most essential step.

....
Laugh, I nearly cried. I left the door open and you walked right in. I had a little bet that you would come back with some fairy tale about the fabulous finish you used and the enormous quantity of signs you made,and you just couldn't resist, though the free materials was a nice touch.

No 'nice touch'. Like any of my posts, the simple truth. I made a number
of signs for a residential estate I lived on. I made them from WPB and
they were still there, doing their job, when I moved away several years
later.

I think you just kept embellishing your story in an effort to confer verisimilitude but have only succeeded in painting yourself into a corner.

...
Now it appears that you spent hours faffing about with FREE paint and FREE ply. Funny I didn't see you pointing out these two very pertinent facts to the o.p....

I would take it as read that any DIYer would understand that making sure
that something is very well painted will involve hours of faffing about.
The fact that I didn't mention I was using free materials is totally
irrelevant.

The O.P. was seeking advice. I advised him not to use wbp as it will not withstand Your answer was to completely ignore the most important point of his query, the cutting of grooves, apparently showing your ignorance of the strength and weaknesses of the material in hand and to offer what I considered to be erroneous advice, the use of WBP in an oustside environment.

Essentially, this comes down to you getting your knickers in a twist
because I dared to disagree with you.

You flatter yourself. I couldn't care less about you disagreeing with me.

Au contraire you have got very verbose embellishing in an effort to prove you're correctness.

Your arrogance in offering your experience as being superior to that of a professional sign writer is breathtaking.

Your assumption that the sign writer just wouldn't take the time to paint it right beggars belief.

Your refusal to acknowledge that contrary to your initial advice wbp might not be the best solution.

Your lack of understanding the weaknesses of plywood and best methods used to overcome this weakness, the addition of edging materials.

What it boils down to is your belief that you know better than anyone else and well dare anyone contradict you.

Colin Bignell

On 07/05/2015 08:59, GMM wrote:

Wow - I never imagined I would stir up a controversy with this one: I
was just trying to devise a way to make these doors a little lighter and
more rigid.

Looks like I'll have to revert to plan A then and use mdf ;-)