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I want to glue four timber beams side by side, stain them and fix some voids with epoxy resin. What is the best order to do it?

Each beam measures 150x150x600mm and is made from beech.

Some voids are 600mm long and up to 15mm wide. Some voids are very small.

I want to use PVA glue.

Here's a picture. The ruler is in cm and 60cm long (in this picture).

enter image description here

Fabic
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    What sort of dimensions are we talking about? Related: what sort of glue? Generally, you'll want to glue up first if using PVA or carpenter's glue. [Edit] your question and make sure we have everything necessary to come up with an Answer. –  Mar 02 '20 at 20:50
  • Thanks @jdv so far. I've updated my question. – Fabic Mar 02 '20 at 21:38
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    What wood is this? Asking this partly in relation to the staining part of your Q, since some woods don't take stain well and caution is advisable about going down that route (if using conventional stain). If you have offcuts it would be an extremely good idea to do some colour tests before committing to staining the workpiece. – Graphus Mar 03 '20 at 08:26
  • Re. the splits, those are very severe! I'm not sure if you know but when pieces like this crack as they have there's no guarantee that they won't try to split again in future (or conversely, try to close the existing splits if the wood goes through a period of expansion). This is particularly the case if any of the beams contain the centre of the tree, something referred to as boxed heart. Boxed-heart wood is generally considered to only be suitable for fenceposts and rustic applications. – Graphus Mar 03 '20 at 08:31
  • @Graphus I've updated my question. The wood is made from beech. It's advertised to build bed frames. I have some offcuts. Thanks for that hint! – Fabic Mar 03 '20 at 09:55
  • Since it's beech (which it didn't look like at all in the photo so I'm glad I asked!) what colour were you hoping to change it to? And what type of stain were you thinking of using? Beech is a dense, fine-grained wood so it doesn't take many stains well. If you're only hoping for a mild colour change to something less pale and cream-coloured just using an oil-based finish will deepen the existing colour quite a bit, and this will mellow over time (noticeable after ~3-8 weeks) to a sort of tan/orange as the oil ages and the wood oxidises. Eventually it'll be significantly darker just by itself. – Graphus Mar 04 '20 at 06:15
  • Re. the epoxy fills when you get to that stage, have you looked at enough sources to have a good idea of how to go about the process? Things like using tape to dam edges (or the opposite side if a split is very very deep) so epoxy doesn't run out, how to minimise bubbles, what to use if you're colouring the epoxy. – Graphus Mar 04 '20 at 06:48
  • I want something like nut-brown-ish. If your telling me I won't get such a dark color it's not a big deal. I'm also fine with just a small color change.

    I've watched and read a few tutorials for filling epoxy. I will try it at the bottom first and see how it works. I'm aware of "damming" and removing bubbles. I've wanted to use a teal coloring but only if the wood gets a dark color.

     – Fabic Mar 05 '20 at 07:36
  • How dry is the wood? If you plann to use enough coloring to make your resin opaque, then it won't matter, but if you are aiming at a translucent fill for those cracks, then I would suggest sealing the surface of the cracks with something to keep water and air from gathering under the resin after it dries. I used green wood for the first translucent river table that I made and six months after it was "finished", small white bubbles appeared wherever the wood & resin touched. It was unexpected and unattractive. Since then, I have sealed even dried wood with lacquer before pouring the resin. – Henry Taylor Mar 08 '20 at 06:13

1 Answers1

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Since it doesn't relate to the other things we're discussing in the Comments we can go ahead and Answer the main query you posted here.

In which order should I glue, stain and apply epoxy resin?

The normal construction order would be:

  • assemble — glue together in this case
  • do any filling that's needed — epoxy in this case
  • and then stain if you're intending to stain
  • application of final finish as the last step.

You fill before staining because you generally have to do quite a bit of surface work — primarily sanding these days — to make fills flat and flush with the surface of the surrounding wood. If you stained first you'd just expose bare wood (irregularly) during this flushing work because the penetration of colouring agents into wood is usually very shallow1.

A quick note on making the epoxy flush
I would advise looking into scraping here if you don't already use scrapers. Scraping is something I promote as much as possible anyway2 but many experienced epoxy users swear by scrapers (of various types) to remove excess epoxy. I'm personally in favour of hand planing to get flush or nearly flush, followed by scraping or minimal sanding as needed, but would only recommend this if you already have a hand plane and know how to use it.

1 Even products promoted as having "deep penetration". This is only deep by comparison to other stains that penetrate even more shallowly!

2 Because scraping is better than sanding a lot of the time (faster, more efficient and leaves a better surface). Plus in the long term it is nearly unbelievably cheaper — one card scraper is equivalent to an almost infinite stack of sandpaper.

Graphus
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    +1 scraping. I briefly toyed with luthiery which introduced me to scraping and I was astonished that this secret weapon for fine woodworking was not better known. –  Mar 06 '20 at 14:54
  • Also, I will note that if the look the OP is after requires coloured epoxy, it might be worthwhile to experiment with different levels and hues of dye on some scrap, and how that works in combination with any tint in the finish. Epoxy will, of course, not take any staining tint very much (if at all) compared to the wood around it. –  Mar 06 '20 at 14:57
  • +1 scraping - it's also much better for your lungs because it generates small shavings, not a ton of superfine dust – Jan Spurny Jan 07 '22 at 16:28
  • @JanSpurny, yup. I've done all I can here to promote scraping as a go-to method for smoothing wood, going back to my Answer here back in 2015. – Graphus Jan 08 '22 at 18:43