How would you make this?

[rusel]

Hi guys
Making a arch way in the garden for SWMBO.
Sizing is it will be made from 90 x 45 treated pine over all hight is 2400 x width 3500. The arch has a diameter of 1340, see attached.
The finished structured will be painted. It will have plants then grown over it.

The question I have is how best to make the arch part and keep the thickness down to 45mm to match the posts?
Hey any other thoughts, please give them.
Thanks
Russell

[vk4]

Russell,

how about making the arch by laminating strips of timber around an MDF form?/

You could also laminate from exterior plywood, which i think would be easier.4.5mm should flex around the radius , and 10 lamination's will give you the arch at the correct thickness and will be immensely strong.

Use epoxy glue for your adhesive and step the ends to attach to the posts,
also use epoxy resin to seal the exposed ply edges prior to painting.

jeff

[Grandad-5]

That would work admirably.
Cutting kerfs into the 90x45 and filling them with builders bog after bending is another possible alternative to consider.
Cheers
Jim

[rustynail]

Could be done as a segmental arch with pieces cut from 90x90 on bandsaw. Joints either half lap or floating tennon. Glue with epoxy.

[rusel]

I was thinking along the same lines of the plywood and the solid wood and just try to think out the easiest one to do but the best structurally over time :? This depends on me and my quality I guess. Which bring me to what's the best epoxy to use and where do you get it?

Russell

[rustynail]

Boat building epoxy glues would be a good start.

[AlexS]

I'd go with epoxied laminations for sure. Check out Adhesive Engineering (http://www.adhesiveengineering.com.au/) for the most suitable epoxy for your job.

[vk4]

Epoxy resins / glue are available from
1, BIAS boating supplies
2, Whitworths ,
3 Bote Cote Australia
4 FGI <

these will be able to supply you with a suitable glue / resin.

Jeff

[wun4us]

Could be done as a segmental arch with pieces cut from 90x90 on bandsaw. Joints either half lap or floating tennon. Glue with epoxy.

Cutting kerfs into the 90x45 and filling them with builders bog after bending is another possible alternative to consider.
Cheers
Jim



Both these methods would be my choice, both of them being made from the same timber as the rest of the structure and best suited to the proposed project. Both also would I think have a decided cost advantage over epoxy bonded plywood.

JMHO

[Artesano]

If you are building it to last , laminated stuff is allways a risk - I would forget about it , but it's just my opinion :; .The same goes for kerf bent arches - seasonal changes will make it rot in a single winter . I would definately make a segmented arch , as it's made for front doors (stuff I've done for living for quite some years , BTW) - You make TWO arches , each half of the desired thickness , and then glue &screw them together .The first is made out of 3 pieces , the other of 2 , so the joints dont match.
A church door frame , with the arch made this way fell on the floor by an accident:doh: - the door was almost three meters high by two meters wide ( sorry:B - 9' X 6' 8" - is that so?:~ ) - and heavy beyond belief - much to our surprise , it didn't come apart , not even a slightest crack:2tsup:

[Harry72]

Putting in a lot of effort to last just a few years... I would be making the whole thing from steel :)

[Peter36]

( sorry:B - 9' X 6' 8" - is that so?:~ ) :2tsup:
Don't apologise Ivan . Oz has been in the process of being metrified since 1970 :)

[rusel]

Wow lots of info to get through here, thanks.
Just rang FGI they suggested the R180 epoxy cost about $35 for a 1kg kit (plus $35 to deliver:no:) I have used this epoxy before and found it very good to use.
I like the plywood it is fairly simply to construct just got to be sure that you have no air between the lamination!
Artesano I was thinking also along the same lines of construction. Let me run one idea I had past you all.
CNC out 6 parts from treated pine 30 mm high that make the arch 1/3 of the hight of arch (45mm arch thickness by 30mm high) then put the next layer of 30mm offset by half so that they overlap the lower layer. Then the last layer is a copy of the first giving a total hight of 90mm and a thickness of 45mm.
All epoxy together with some screw to hold it till glue sets.
Seeing that I can cnc the parts out I could lap the joints where the segment meet or even key hole them. Do you think this would help or just be over kill?

Russell

[rustynail]

If you are going to use triple layer you wont need end joints. Only thing is, fresh glued pieces want to slide in all directions even the screws can be a bitch when being driven. Short locating spikes would be better (cut off nails will do.)

[rod1949]

Putting in a lot of effort to last just a few years... I would be making the whole thing from steel :)
:repplus:

I'm with you Harry :2tsup: The longest lasting and most practical way to go.

[Peter36]

:aro-u:
Hot dip galvanized and powder coated. :)

[rusel]

Yes I like steel too but SWMBO likes timber got it :oo:
I can get some 4mm extra ply for $30 a sheet from mr plywood but he not sure it will bend that tight a curve (1340mm diameter) I feel it would at 90mm wide. Has anyone done something similar?

I will take on board your suggestion rustynail

Russell

[Grandad-5]

I've been asked to build a few different garden structures over the years for people wanting to grow a vine over.
Only one arch type like you're describing and that was for myself and was made from steel.
The reason I'm posting is to point out that what you grow on it has a bearing on how you build it.
Once the plant has reached maturity and covers the whole structure you will NOT be able to do any painting or maintenance on it ever again.
This is something that should be kept in mind at this early planning stage.

Something like a Wisteria will grow strong enough to be self supporting, but the more common Jasmine style vine will require support for life.

As mentioned, I built the arch for my own SWMBO out of gal RHS for just that reason. (I had the sections rolled to my desired radius at a local fabrication shop.)

May I humbly suggest this be discussed with the explanation that once the plant matures, you will never see that arched part again. Timber/steel....will make no visual difference.
The fence parts going out each side can still be timber and give that timber look your wife is chasing.

[ian]

and if the frame is powder coated brown or the right shade of grey, it will look like timber too

[Grandad-5]

and if the frame is powder coated brown or the right shade of grey, it will look like timber too
Not wishing to hijack Ian, but just how long term is powder coating?

[rustynail]

You need to remember that exterior plywood is only radiata veneers with a water proof glue. Not exactly what you would call long term. Marine ply would have better durable timbers but expensive.
Either way, ply would not be a real good option.

[ian]

Not wishing to hijack Ian, but just how long term is powder coating?
I don't really know. But I understand that powder-coated steel should outlast galvanised steel. and for a trellis, it should last more than long enough

[rusel]

Had a long discussion with SWMBO and now she likes the idea of making out of steel because it can be made finer looking. :roll:
I am now looking at 25mm square tube. Have had a over the phone ball park for the two arches at $150, rest of the steel is around $60. This is all in gal tube.
Weld and cold gal them and then some etch primer and top coats.
Still might put it up on some post supports concreted into the ground.

Thank again for your opinions, most helpful as it has got us closer to what we really wanted

Russell

[Grandad-5]

Have had a over the phone ball park for the two arches at $150, rest of the steel is around $60.
I had a single piece of 25mm RHS (I supplied steel) rolled into an arch for $50 locally.
Therefore, 2 arches inc the steel for $150 sounds reasonable.

[The Bleeder]

Not wishing to hijack Ian, but just how long term is powder coating?


The bull bar on my landcruiser is powder coated and it still ok after 30 years.

BTW it doesn't get much TLC

[rusel]

Got the arches from roller last week as well as the rest of the Duragal. Spent the weekend cutting and welding it all together. Got some good tips from another post on the forum about welding the gal tube.
In the photos it just sitting in place still to concrete the support post in, will do this when fully welded together and have it sitting square over the holes then just add concrete.
SWMBO Loves the gal colour so that the finish done. I did cold gal the welds and I will get the spray on duragal finish to bring it all to the same colour
The photos show the welding of the arch and the bracing to take out the twist after tacking it together, it came out spot on after fully welding it up.
Other photos are from the house and from back of arch.

Thank again to all the chat as it helped work out what we wanted. Nothing like what it started out with.

Russell

[Grandad-5]

Top job Russell.
Looks great.

[ian]

Looks great and best of all you report SWMBO is pleased

[vk4]

Russell,

Looks great, the kids will love you for the climbing gym,:) seriously it does look really good and the climbing Plants will love-it

.

Jeff
vk4