Client has requested an "Aquarello with interest" finish for her outdoor patio. The walls are typical "board and batten." We are going to remove the batten and fill the cracks between the plywood sheets. So, bascally, the substrate is 3/8" plywood.

I haven't done this finish before. Could someone share what would be the proper layering of ALL needed product to achieve this finish properly under these conditions?

We are going prime the plywood with oil base primer first as per instructions from Doyle's employees....

Thanks in advance
RanMan
http://studioabbellire.com

Hi,

The potential issue lies in the substrate’s stability or lack of it in the outdoors. The concern is flexing of the substrate under thermal cycles and wind load.
Consider the use of Velnovo as your base plaster. It’s made to handle the extremes of stress that will exist outside.
1) Fix a Quartz over the oil primer.
2) Velnovo; Call SOIP for instructions (Be sure and add by volume, 40% Portland cement - as per manufacturers specs.) Yes 40%! Darby if desired.
3) Aquarello primer - two coats - thinned as per manufacturer for exterior use.
4) Aquarello finisher - two coats - thinned as per manufacturer for exterior use.
5) Relax - enjoy the patio - before your next project!

David

Good advise David.....if this was my project I would, in addition to David's advise:

Treat this plywood as you would the exterior sheathing of a new construction.... I would apply paper and mesh and then give it a good scratch coat..... I don't believe that simply filling the cracks and taking it from there will be a very long lasting finish without joint cracking...........it would last for some time but with the amount of layers and cost that are required for an exterior Velnovo/Aquarello....the initial preparation of the plywood with mesh would not be unreasonable.....

p.s. I have an exterior Sunroom to do this spring and it is plywood siding....I plan on adding the mesh, paper, and scratch before commencing the Velnovo/Aquarello.
just my .2$

Greg

This message has been edited. Last edited by: greg,

Hi Greg,

Great method you suggest!
Very good advice from whom I believe is likely the expert of large scale exterior Velnovo applications. Several thousand feet in the heat of summer is wow -- hot!

I almost said something similar as you did, but opted for the simpler approach.
Maybe I misread, but I thought full sheet plywood is being used. Seams should bridge with Velnovo.
Each coat of Velnovo can be up to 8 millimeters (about 1/3”) thick.

I offer an alternative method for results similar to wire mesh. The use of EIFS fabric mesh attached with long exterior grade stables. One coat of Velnovo, followed by a second coat of the same. It's easier than the mesh and scratch. Not better, just easier.

You have another New Mexico exterior project – wow!

Take care,

David

This message has been edited. Last edited by: David.,

Ranman,Lisen to the pro's who know.I know I sure do.
Dave and Greg,Keep up the great advice.
Ken

Thanks a bunch folks...!!

Concerning the mesh that was mentioned, what type and/or where is it available.

RanMan
http://studioabbellire.com
http://infauxworld.com

I re-read David's post and he is correct, in that it is a plywood surface and I think that the joints are going to be in the headers above the french doors... small wall, just 239 sq. ft. not counting the two 8 foot french doors in them.


RanMan
http://studioabbellire.com
http://infauxworld.com

Both types are made in different sizes, thicknesses, etc. Check with local building suppliers for availability. Some on-line research will yield good info on types, recommended uses and their application.

Metal: Diamond lath.

Fabric: Use alkali-resistant fiberglass mesh - different sizes, etc. are available for either EIFS or stucco.

David

Concerning the addition of the portland cement to the velnovo, I opend the bucket of velnovo to check it out, didn't mix it up but merely checked consistency...

Does the portland go into it dry...it appears that would wreck it? I'll be getting to that phase in a day or so...

Thanks in advance

RanMan
http://studioabbellire.com

RanMan, Not a good idea to add dry because your mix will rapidly set up. It is best, and recommended to hydrate the Portland Cement before adding to the Velnovo. It is recommended to mix a thick paste of P.C. and then add to the Velnovo and drill mix at a low speed....Hope that helps.

Greg

Thanks a bunch..I figured that was the case after I looked in the bucket of velnovo and saw the scant amount of liquid in it..

I spoke to James at SOIP and he said to make sure I mixed it so it doesn't set up too fast. Just out of curiosity what would be the "bucket life" of a batch.... right now we're running in the mid 50's temp wise...

Thanks in advance
RanMan
http://studioabbellire.com

At that air temp, multiple hours. More than enough time, with time for a lunch break or nap! You really have to be concerned when it is 95 F plus....

Hey again...

Another clarification please if I may so impose :-)

James sent me letter from a discussion here which stated that the amount of portland cement to add to the velnovo was 20% instead of 40% stated further up in this thread. Which would be the best way to go?

Also when you say "add 40%" that means the equivilant of 40% of the contents of the velnovo bucket, i.e., 40% of a 5 liter bucket would be 2 liters cement added....?

once again..thanks in advance

RanMan
http://studioabbellire.com