Help needed for novice with slab.

[muppeto]

I was the one and only bidder on an eBAy slab table. Tookdelivery and found a 3500 mt x 900 x 100 slab in need of serious repair seepics attached. Not sue what the timber is, but its one piece and apparentlyvery old. My plan is as follows:
1) remove old putty and silicon;
2) strip old varnish with "polystrippa";
3) fill holes with clear epoxy resin;
4) sand - with belt sander - from 50 and down to 120;
5) seal with clear finish.
That sound easy but here is a list of my questions.
a. The wood is soft under the areas that wereputtied - do I remove all the soft wood?
b. Is a problem if I get polystippa down inside theholes?
c. Can I apply epoxy to the side of the tablewhilst it is laying flat?
d. I will have a many questions about sealing whenI have finished prep.




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[Master Splinter]

1) remove old putty and silicon; Yep
2) strip old varnish with "polystrippa"; Yep...but personally I'd use a sander.
3) fill holes with clear epoxy resin; Yep...but suggest black (colour with some black oxide or coffee grounds or.....) and thicken the epoxy up with something (sand, wood dust, talc) to increase its bulk/reduce cost.. (see here for more epoxy information - Epoxy by the Leading Epoxy Manufacturer | WEST SYSTEM Epoxy (http://www.westsystem.com) )
4) sand - with belt sander - from 50 and down to 120; 80 to 200 would be better
5) seal with clear finish. Oil. oil, oil, oil and oil (unless outside, then it's epoxy, epoxy, epoxy and a UV protective varnish over that)
That sound easy but here is a list of my questions.
a. The wood is soft under the areas that wereputtied - do I remove all the soft wood? It would be be good to.
b. Is a problem if I get polystippa down inside theholes? Not if you get it out...I'd say you can probably use a small wire brush in some of those cracks!!
c. Can I apply epoxy to the side of the tablewhilst it is laying flat? Yep. BUT make sure you don't stick it to anything! Plastic is your friend in this case!
d. I will have a many questions about sealing whenI have finished prep.

[muppeto]

Thanks. I am looking forward to this project and I think I do it well it will turn out OK.

[muppeto]

The old putty and silicon has been picked out and I have removed the old varnish with belt sander and course sandpaper. Some of the wood in tose holes is soft. What causes that?


Next I want to keep sanding with finer grade sandpaper and then fill those holes with epoxy resin. Any suggestions/tips on how I do that would be greatly appreciated.






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[Master Splinter]

Various species of bacteria and fungus can break down the lignin in the wood, causing soft bits. That pic 3 looks like wood borers. My treatment for that would be to pour some thinners over the area; if they are still alive, they won't be after that!

Don't do any more sanding for the moment; fill the holes with epoxy first, then back to sanding!

Mix ratio for epoxy needs to be pretty accurate; typically its 5:1 (West System Epoxies) or 2:1 (Botecote (http://boatcraft.com.au/Shop/index.php?main_page=index&cPath=15)), so measure carefully (and don't mix more than about 250ml at a time to avoid a runaway exothermic reaction), and do a small test batch first to see what colour you are after.

Mix the epoxy, then use a cheap brush to apply it to the inside of the crack, then thicken and or colour the remaining epoxy and pour/putty knife the mix in. Depending on the effect you are after, you can use some of the powder pigments found in art shops for some very artistic effects (see some of the pen making threads here for some of the things they do).

Filling and Fixing Knots in Wood Using Epoxy | The Wood Whisperer (http://www.thewoodwhisperer.com/videos/fixing-a-knot/)
Wood Knots & Other Defects - YouTube (http://www.youtube.com/watch?v=-qMx-DVrlGY)

You may also find that butterfly keys are an interesting addition to the top
Bowtie Keys Butterfly Keys - YouTube (http://www.youtube.com/watch?v=DLQkk-x5CeI)

[muppeto]

Fantastic tips. Thank you so much.

I have started to collect the sawdust from all the sanding and intend to use that as a filler when it comes to filling the cracks on the side with epoxy.

The slab is too heavy for me to place on ots side so I was thinking of wrapping the working area in glad wrap and injecting the epoxy (through holes in the glad wrap) with a very bore needle and syringe. I figure that wrapping the entire area in glad wrap (lots of it no doubt) will both contain and shape epoxy consistalty with the free form edges of the slab.

Muppeto

[Christos]

It is a different way of thinking to use glad wrap and can see some logic to your concern of tilting the table. I would prefer to have gravity help me fill the cracks. The underside of the table is not seen but also something to consider if this is soft or flaking so flipping it might be needed?

The size of the cracks could run deep and you might find you will be using quite a amount of epoxy and saw dust will help. Small batches as Master Splinter has mention is best way to go.

[Master Splinter]

I'd caution against using the sanding dust as a visible filler; firstly because you have sanding dust AND old varnish dust, so the colour might not come out the way you want, and secondly, because (in my opinion) it always looks like cr@p. In anything but small areas, it comes out as a lifeless, bland approximation of wood screaming out 'Hi, I'm plastic pretending to be something else!!!' - it always reminds me of that horrible 'flesh coloured' plastic used for hearing aids. Pretty much the 'Donald Trump toupee' of woodwork.

My first suggestion would be adding some red and black tinters (I've used the Feast Watson stains (http://www.bunnings.com.au/feast-watson-50ml-oak-prooftint-interior-stain_p1569883)) to create a translucent sap like colour.

Or...go wild and use something that contrasts with the timber:
http://www.woodworkforums.com/f204/some-my-recent-casts-177799/
http://www.woodworkforums.com/f204/cast-jacaranda-root-nodules-174191/

[BobL]

I'd caution against using the sanding dust as a visible filler; firstly because you have sanding dust AND old varnish dust, so the colour might not come out the way you want, and secondly, because (in my opinion) it always looks like cr@p. In anything but small areas, it comes out as a lifeless, bland approximation of wood screaming out 'Hi, I'm plastic pretending to be something else!!!' - it always reminds me of that horrible 'flesh coloured' plastic used for hearing aids. Pretty much the 'Donald Trump toupee' of woodwork.
I agree - don't do it. It is impossible to match so it is better to create a contrast. Just use plain epoxy and tint it if you wish. Try it out on another piece first.

I've never been able to get the Gladwrap approach on the side to work very well, the glad wrap will bulge at the bottom of the crack and be under filled at the top. Get some help to tip the slab over - it will be worth it.
Just ask for help from a local WWF member - they will very readily help out.

[muppeto]

Once again I am very greatfull for the tips. I venture forth with hesitation and excitement at the same time and wise advice gives me the confidence not to wreck this thing as I progress through the project.

Adice on the use of saw dust duely noted (no Donald Trump toupees). I will propably end up with a tint. Time to consult the partner.

As for the glad wrap concept I figured I would have brace it to stop it from saging. Maybe something like a firmly wrapped linen cloth. The bottom of the table is pretty solid. It's just those sides that I forsee I will have epoxy spilling all over place and make a mess.

[Master Splinter]

Duct tape is a good and cheap containment medium for epoxy. Wipe the wood surface with thinners a few times to remove any sanding dust so it sticks well, and reinforce larger areas with corrugated cardboard or scrap timber to reduce bulging.

[muppeto]

Ok will do. No glad wrap.
Thanks to the advice I am pretty clear about the next step.
Finish cleaning out the cracks and crevices, getting ride ofthe soft wood. Thoroughly clean, dry and tape the working area. Lightly coatthe working surface areas with epoxy and begin to fill using no more than 250mls of the tinted epoxy at a time. Let that cure overnight and repeat.

I will test a small area and if it works out I will fill all the holes and post pics.

Thanks again for the advice

[Christos]

Do keep posting I would like to see the before and after shots.

[fields]

How did the table end up?

[rod1949]

Can see why you were the one and only bidder... so how much did you pay for it?

[Hermit]

I'm still interested too. How did you go?