Clear finish for Tas Oak beams?

OK Guys & Gals
About to pop the first Curved beam out of the Jig & get to cleaning up glue, sanding etc... and finishing.
Still trying to work out what i should use as a finish. Anyone had similar job & what did you use?
Details as follows.
Five beams - Tas Oak - 100mm x 250mm cross section.
Beams are 5.5m straight with a 2.4m dia semi circle on the end.
3 beams are indoors, one has one face indoors & other face under cover.
5th is outdoors (picture beam under roof at the edge of a verandah.
Want a clear finish, not high gloss. Outdoor beam faces east so will get full morning sun.
Have been considering:
1 - Tung Oil base finish (have to keep re-doing every year)
2 - Clear Acrylic (never used it before)
3 - Epoxy - ????

Any feedback greatly appreciated
Thanks
Peter
Ozartisan

Quote:

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Originally Posted by Ozartisan

OK Guys & Gals
About to pop the first Curved beam out of the Jig & get to cleaning up glue, sanding etc... and finishing.
Still trying to work out what i should use as a finish. Anyone had similar job & what did you use?
Details as follows.
Five beams - Tas Oak - 100mm x 250mm cross section.
Beams are 5.5m straight with a 2.4m dia semi circle on the end.
3 beams are indoors, one has one face indoors & other face under cover.
5th is outdoors (picture beam under roof at the edge of a verandah.
Want a clear finish, not high gloss. Outdoor beam faces east so will get full morning sun.
Have been considering:
1 - Tung Oil base finish (have to keep re-doing every year)
2 - Clear Acrylic (never used it before)
3 - Epoxy - ????

Any feedback greatly appreciated
Thanks
Peter
Ozartisan

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IMHO, none of the above.

Tung Oil base finish would have to be done at least once a year, probably twice a year. You will do that for the first year and then let it slide, so it will look sh*thouse very quickly.

Clear acrylic not flexible enough for use on wood, great on slate etc, not wood.

Epoxy, in clear has very poor exterior durability.

So says you, what do I use wiseguy?

I would use a marine varnish, I used Cabots' Exterior Marine Varnish on a cypress top for an old Singer sewing machine stand and it is standing up very nicely. I know that will be a bit glossy to start off with, but it quickly settles down, if not enough, use 0000 steel wool to get a nice satin finish
.
Whatever you do, don't use a satin finish outside, it uses silica based flatting agents and last about 3-6months outside, great for inside though.

I'd separate the internal finishes from the external.

Outside, it comes down to how often you want to re-finish. Me, I'd go with the best multi-layer sikkens approach, and review it for wear and tear every year. Depending on location, and exposure to sun and weather, you should get 3-5 out of it.

Inside, go with whatever you like. Do some tests with various finishes and choose the one that looks best. The beams are out of the way and whatever you do is going to last for years and years.

woodbe.

Oh,

I forgot. How about some pictures of your beams!

woodbe

I'd go for the sikkens anyday,

Got a cypress chainsaw carving living in the middle of the bush,
its about 12 years old and the finish is still very good

Thanks Guys - your input is very much appreciated.
Will contact Sikkens distributors & have a chat to them - don't know if anyone stocks their stuff in our neck of the woods.
Was going to pop the beam from the jig this morning - but all the eaves sheets arrived last night - wantto get them painted BEFORE they go up tomorrow. Sure beats painting upside-down, cutting in etc! - Especially since some will be over 5m up!

Woodbe - here are a couple of WIP pics for you - will post more after cleanup, sanding & finishing.... then of course - eventually beams in situ.

Found a great retailer here in Taree with good stocks of the Sikkens product.
Here is another WIP pic - one end of the beam standinh (upside down) in the shed awaiting clean-up & finishing

Not trying to be a wise guy, but...

"Whatever you do, don't use a satin finish outside, it uses silica based flatting agents and last about 3-6months outside, great for inside though"

You may not know this, but silica based flattening agants are use in most exterior coatings and paints as a natural sun blocker, these traslucent particles block the sun's rays by deflecting them, just as the pigmented colorants do, both of these particles are used s "blockers."


http://iswonline.com/OnlineFeatures/...of%20Finishing
http://www.macsimmons.com/

Macs, I have spent most of my working life as a paint chemist and yes I am aware of the silica you are talking about, however they are not flattening agents.

Silica based flattening agents work by sticking out of the film, hence you finish up with either a satin or matte finish. These particles are hygroscopic, ie absorb water, and act as wicks and the surface breaks down.

BTW, your first link doesn't work.

Thanks, I'll check it out.

MacS

Coming from the other side of painting (auto) I have always used automotive paint to replace household type material. We had both available to us but without exception they would out perform those used normally in domestic use.

The 2 pack urethane enamels are far superior (they have great UV protection ) in their make up due to the more severe conditions they are put under.

Virtually all cars now have a clear top coat over all colours which is guaranteed for between 10 to 20 years on the vehicle. It can be brushed or sprayed ( use the correct mask etc if you spray) and will give better performance than marine varnishes. I have it on a veteran car on wheels and other exterior timber work and also an exterior screen door facing north which had marine varnish on that lasted on 2 1/2 years and its still as good as new after 5 years.

Its been over 15 years since I did tests on both 2 pack urethanes and normal marine and household enamel clears nitro cellulose and shellac and I no longer have the exact results but all had failed and the 2 pack urethane clear was still ok at the end of the test. The current ones have been varstly improved since those days.


Check out the local panel beaters for some information about them, they can give you details of the ones easily available in your area or the distributors. I would also ask about the new "ceramic" clears which have just arrived on the market. They are designed to help prevent vandalism and other damage to the clear due to their hardness these would offer some extra protection especially to the exterior wood.

These are usually high gloss finishes but can be flattened off to any gloss level by burnishing or adding a flatting agent. Often areas on vehicles have low gloss sections to prevent reflection.

The final choise is yours but I would be looking at all the options especially after all the work you have put into the manufacture of your beams.

A big thanks to everyone for your valued input.
Sikkens won the day.
Penetrating sealer coat of Cetol HLS, followed by 2 coats of Cetol Filter 7.
Just applied the last coat on the first beam.
Will try & get the chippies to erect it on Friday.
Segments for second beam are half done - another glue up on friday perhaps!

Peter,

I just visited your web site, and I enjoyed my visit.

I had sent you and e-mail, but it was returned, you should check your address as it could not be found.

Good Luck in building your dreams, may they all come true.

MacS