Rivali varnish, another question!

[Vindo Joe]

Hi people,

Well the repairs are completed on Tucana see below, the site is posted on the Vindo net on Yahoo:

http://hem.passagen.se/vindokalle/vindonet/tucanarepair.htm

I stained the wood using Minwax gel stain, very nice color and it went on ver evenly. Then soakd it in CPES in hopes of locking into the surface and promoting adhesion for the varnish. Now I'm on my fourth coat of Rivali varnish and I have a problem, I think.

The surface is very bumpy like a cross between orange peel and fish eyes. I sanded each coat with 220 wet paper and after the third coat I went back over it with a red Scoth Bright pad untill the surface was all evenly abraded. Then I washed the surface down with Isopropyl alchohol and wiped it all down with fresh clean rags in one direction. Just finished the fourth coat and it looks like orange peel again! Can this happen if it put on too heavy? It looks fine when I first apply it but about half an hour later the craters start o appear. This is really slow drying stuff, no way will a brush mark ever show up after it sets.

I love the color but I can't stand the thought of another coat going on like the last two.

Any thoughts?

[Wild Wassa]

Hi Joe, Orange peel is uneven thickness combined with uneven drying. If heat is quickening the skinning of the film, this will 'enhance' the effect. Skinning happens first but this breaks up into mogul (like) or gullies. Could your scratch pattern be too deep or too sharp?, drawing a lot more paint than you want.

Just as water will bead so can paint and is generally an adherance problem. The beads are tiny, giving an orange peel look. Body oils on the surface don't help.

Residual water in cracks and caves with oil based materials, and epoxies, little bubbles and outgassing. Infact outgassing has a lot to answer for with slower curing emulsions. Also if there are solvents in the air this can cause a problem, with different materials.

The fisheye(s) that I've experienced have been caused by direct heat, in sunlight in fact, about a week after the painting. It was the heat. If you are using heat, use it to stabilize the room temp only. Do not 'blow' air across drying paint. Changing the air is different, 5 or 6 air changes an hour for the painters (at least!). Excess humidity with oil based materials can result in different surface types and bubbles.

When the paint or varnish starts to dry and set, it shrinks and little bumps appear under the surface from nonvisible artifacts. Make sure your materials aren't gritty. There is the DUST as well. Using the isopropyl alchohol is a chemical stage requirement or a speed technique or an anti-dust?

As a painter I am always aware of standing wood grain. The grain was flat when you started painting? It had time to stand up? End grain! Minute but still endgrain after sanding. The end grain can also push the paint up without breaking the surface of the paint or varnish.

With the 'compatibility' of Miniwax, CPES and Rivalli, I don't know. Are the materials known to be compatible? Allow the coats to cure longer, after checking the CPES instructions.

Warren

[ 05-21-2002, 07:58 AM: Message edited by: Wild Wassa ]

[Scott Rosen]

Joe,

It looks as if we're practically neighbors. I've used Rivali so maybe I can help. I have used it over CPES with no problems, so I'm certain they are compatable. I don't know anything about the stain, however. I would think, though, that the CPES would act as a barrier between the stain and the Rivali, so the stain shouldn't be a problem no matter what.

Here's what I think. First, Rivali is very thick and cures very slowly. It's not an easy product to use. You should be thinning it from 10 to 20% with the proprietary thinners. Do not use any thinner except the ones made by Rivali. I'd use the cold weather thinner for this time of year. Brush it out really well. Let it cure for two days before sanding and recoating.

Do not wet sand. There are lots of problems with wet sanding this stuff. First, Rivali takes weeks to get a full cure, so if you wet sand within a couple of days of a coating, then you are making a pasty, watery mess with partially cured varnish; you're breaking the cured surface and wetting the partially cured varnish underneath. Second, even if the varnish has cured for a month, unless you are able to wash the sanding residue off with lots of fresh water and mild soap, and then let the water dry overnight, you will only come to grief with the wet sanding. I suspect that your problem is mostly caused by the wet sanding.

Dry sand lightly with 220 between coats. Use mineral spirits or turps, not alcohol, for your wipe down. Use the two rag method--one rag with the solvent and then a clean rag to wipe the solvent off. Change rags frequently. When the solvent is completely dry, go over it with a tack cloth. Then apply the varnish. You need to varnish early in the day because of the slow cure.

Rivali is without a doubt the most beautiful varnish made. But it's like a beautiful Italian woman: it's tempermental as all get out, runs hot and cold and is often unpredictable. To get a good finish, you need careful handling and you have to go with it's moods. And you will have occassional bad days with the stuff.

[Wild Wassa]

I certainly agree with Scott about the 'moods of paint'. A change of two degrees and it's as though you are using a different product. Different flow rates for sure. A change of 5 or 6 degrees and it is a different product.

[Vindo Joe]

Scott,

I was just about ready to go back to my old tried and true "Captains" varnish (borning!), but then your poetic ending reminded me of why I varnish in the first place.

When I'm flowing this onto the mahogany, I crank up the opera on the stereo, and I'm remimded of being at the blue grotto in Capri.

On a more practical note, you indicated that alchohol is not good for wipe down, can you tell me why? The instructions indicate it's OK as long as it's not denatured.

Thanks

[Scott Rosen]

Nothing scientific. I've always used mineral spirits or turps and have never had the problems you mentioned. I'm applying the "if it works, stick with it" approach.

[Wild Wassa]

Joe, What have you read about the longevity of the Miniwax stains and what pigments are being used, the organics or minerals? Be it seperated from the varnish by CPES or not. No matter how much neutral density has been added do you think this Miniwax will be as unstable or as fugitive, as are other stains?

Can the Miniwax be used on wood without a wood sealant? Stains tend to be VERY unstable if proceedures are skimp. Also you are using three layers? of solvent thined media. Wood grain can stand up, due to the solvents alone. If you are not allowing the underlying layer to polimerize
the paint is still soft. The more coats the more bumps.

Is Miniwax, oil and wax based? Does this wax? suffer from heat effects and mottling? There is UV and IR involved.

I'm also interested to know if your painting problems have been solved, once you have had a chance to redo the work. Procedure will not usurp prep, in the first instance.

Cheers, Warren.

ps, painting is not a matter of do this then do that. It's a matter of do this then adjust that. Sand paper adjusts everything?

[ 05-21-2002, 08:46 AM: Message edited by: Wild Wassa ]

[Vindo Joe]

Well I sanded the last coat using 180 grit 3M gold paper (dry). I was able to get about 80% of the orange peel smooth. I was afraid that if I got it totally smooth there would be no varnish left! While the overall thickness was good the craters were pretty deep. I'll let you know this weekend how the next coat comes out.

It was a funy thing last time though. When I brushed it on it looked perfect. About half an hour later I could see the craters start to form (shrink back?). In any case though I will put on another coat of the Rivali brush it out thinner than last time and see what happens.

The Minwax gel stain is rated for outdoor use as it's intended use if for exterior wood and fiberglass doors. It's an oil base stain I'm not certain what the pigment material is. I called the companies customer service department and they tought it would be OK for the application. I also spoke to the people at Smiths and Rivali and the consensus was that it would work. Time will tell for sure.

Thanks for all the advice people I'll keep you posted.

[Art Read]

Is this Rivali stuff really so "different" to apply from "plain vanilla" varnish? I know it looks really good, but why is so finicky? I've never messed around with stains, but the best results I can get with any varnish, CPES or no, is to basically slop it on good for the first few coats and then sand it aggressively enough to get a nice "feeling" surface before continuing. I don't worry too much about bugs, pollen, dew, dust, the phase of the moon or anything else but runs, sags and holidays until I'm two or three coats from the "finish" coat. (Which I always have to do over anyway...) That's where I concentrate on a good build up and nice finish... after I've got a good "foundation" of fresh, but fully cured and smooth varnish down. Seems to me that sometimes people expect too much out of those first few coats. They ALWAYS dissapoint the next morning even though they looked great going on.

[Scott Rosen]

Art,

The Rivali varnish is a lot different from the other stuff. It's practically alive. It uses a resin "system" that is completely different from any of the others. It's beautiful to look at, but it's softer and less abrasion resistant than the others. It's no where near as tough and durable as a phenolic or alkyd or baklite or polyurathane varnish, although it has pretty good UV protection. You could never use Rivali on a cabin sole, for example.

[Vindo Joe]

Well I just put another coat on and it seems to be filling in and smoothing out. I sanded dry with 3M gold and wiped it down with alchohol. Not perfect yet but I think it's just a question of more build up. The color and gloss is really starting to look beautifull.

I'll keep going and see what happens.

By the way I've spent a lot of time on the phone with the people at Rivali Yacht Systems. Fantastic people very helpfull, they even dropped supplies off at the marina for me one day! Highly recomended.

Scott if your ever in the Brewers yard in Essex look me up. We can trade Rivali stories.

Thanks
Joe

[Vindo Joe]

I got it!!!

I found out why I'm getting "fish eyes" in the Rivali.

It's the TDS caulking I'm using to seal the joint in the deck and the coaming. As part of the repair I reefed out the caulk joints. When sanding the wood clean I also sanded the remaining traces of caulk with the same sandpaper, probably grinding small particles of caulk into the surounding wood. In this months Wooden Boat Magazine they are reviewing the TDS product and warned that it can cause fish eyes in the finish if not carefull.

I can't believe I spent all that time cleaning the cabin down to clean wood and in the process contaminated the surface!

It's become better with each sanding a re-coating. I'm not giving up on the Rivali, the gloss and color are too beautiful!

[Scott Rosen]

Good to hear you solved your problem, Joe. TDS is a silicon product, so it will create problems with paint and varnish. I'll try and stop in and see Tucana. Patience is at Harry's in Westbrook, so drop in when you're in the neighborhood.

[thechemist]

As you know by now, surface contamination causes craters and silicone caulks can transfer some of their silicone non-reactive diluent oils to a surface the cured rubber is rubbed upon.

Aromatic solvents swell and release and clean up silicones. That is the aromatic solvents, not aliphatic. Odorless mineral spirits is the aliphatic type, straight hydrocarbon chains. Xylene is very lightweight aromatic thinner. Aromatic 100 is slower-evaporating and actually attacks silicone residue better. It will even lift it off of porcelain, if you have some bothersome caulk residue around a tub or shower.

[Vindo Joe]

Scott,

I will try to get over to Harry's soon.

Chemist,

Is "Aromatic 100" a brand name? Where can I buy these chemicals retail? Will they attack the varnish and ruin the finish?

Thanks

[thechemist]

Aromatic 100 is an industry generic name, as are acetone, MEK, toluene and xylene. Lacquer thinner is a hodge-podge mixture of stuff that falls within a vague set of guidelines. Mineral spirits is a fairly consistent blend of certain types of aliphatic, also called paraffinic hydrocarbons. Neither aromatic nor aliphatic solvents will readily attack cured varnish, although both will dissolve the uncured stuff. Paint and coatings manufacturers use it in some formulations or reducers. You may be able to buy cans of the generic solvent xylene in the same sort of stores that sell miscellaneous solvents such as MEK, etc. Some paint stores also sell such things as reducers for their paints, usually epoxy coatings or some antifouling paints. I would spend some time on the phone before running around. Unfortunately, you may have to actually go to a store, look at the ingredients warnings on the side panel of their solvent containers, and then ask to see the MSDS for that product to see if the one that says "Warning . Contains aromatic naptha" shows on the MSDS it is mainly that, or only ten percent. Reason being, the store clerks may neither know nor care, and blow off the phone call. I wish I knew some commercial product that was exactly that stuff sold under another name, but I don't.