i’ ve have 4- 14’x 4″x12″ doug fir dressed timbers that i am replacing under a covered up and over breeze way between the house and garage. the original beams are 110 yrs. old.
before i retro-fit them into place i would like to seal them with shellac. standard zinsser, i believe 4 lb. cut. now what worry’s me is the moisture content ( off hand i’ll say 18%+- 5%)of the beams and the application of the shellac . i’m was vasilating between spraying it or brushing. but brushing seems it will win out. does anyone see any problem in this , or perhaps another material to use. again, any help would be appreciated. april 7 3:41 and snowing where is spring……….. thanks bear
Edited 4/7/2003 3:44:44 PM ET by the bear
Replies
I don't quite get it. Are you replacing the old beams with new DF or just re-finishing them?
replacing and would like to to put 2-3 coats of shellac to minimize any cracks or checks. this is new growth as opposed to old growth i'm replacing.....bear
Cracking and checking will be more of a function of how wet the wood is upon installation and how dry the air is that it gets exposed to. I've had good luck with a 50/50 mixture of boiled linseed oil and turpentine brushed on heavily and then wiped off. Turns a nice golden brown over time and does a nice job of grain and color reveal.
johnny d-i can see that mixture really being a nice addition...... but....... one other thing i forgot to mention they'll be painted. how will paint mix with the linseed oil/turp mix. will i have to stay with oil paint is latex out, i'm going more for sealing. like i've said new growth with knots and blemishes bleeding threw.
then go with the shellac. I'm trying it now under varnish...so far so good. The linseed oil is probably best for clear, although the old timers used to mix linseed oil with red barn paint.
thats gotta look pretty good that mix w/varnish. i'll definitely keep that one in the back of my mind. the reason i picked shellac was the alcohol and water(moisture) are soluable with each other . just wanted verification . thanks johnny stay well......bear
I'm afraid that checking and cracking will be a function of how fast they dry rather than any thing you put on them.. any kind of paint will dry and crack when the timber underneath it shrinks.. The timber will shrink as the water is removed.. If you have a decade or so you can do what they did to the timbers on the USS Constitution (old Iron sides) take the timbers out to sea and sink them.. the bonded water that is inside of the timber will be forced out and replaced by sea water.. once they are fully water logged (about 7 years) you can bring them up and air dry them (about 3 years) and checking /cracking will be minimized..
frenchy- thanks for the response, some great history there .i'm concerned with in a years i'll seal with shellac before it's re-installed. than heavy coat of oil-based primer, two coats of oil based paint. the concern also is pitch pockets, knots, so forth and there are a surprising amount in one of them. the only reason why i didnt return it it's incredibly straight and tight grain.
on another note been reading your post's about your "boss", you need to take a warm weather vacation with all the trimmings. new orleans is a nice place to go for 4-5 days food and if you imbibe in the grain or grape . it's a fun place. any how thanks for taking the time out for the resopnse.......... bear
I'd go with the shellac also for your purposes. While it's one of the best barriers to moisture vapor exchange and thereby will slow the arrival of the fir to EMC, it can't prevent it from eventually reaching EMC. I do think though that slowing the rate at which it arrives there should minimize the almost inevitable checking.
I might be inclined to use Zinnser's new Seal Kote product however rather than the standard product. Seal Kote is dewaxed shellac and will probably provide you with a better surface bond to the primer.
Knowledge is power, but only if applied in a timely fashion.
goldy -thanks for the pointers, i'll look into dewaxed seal coat... cheers - bear
I'm agreeeing 100% with goldy. It will help seal some of the pitch bleedout too, tho that's a permanent problem when you use DF..
Excellence is its own reward!
thanks pif- i'm leaving right now for the paint store , thanks again for all responses. april 8- 6:26 am- and no snow- spring would be welcome........ slainte' bear