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How do I get the grain back?

4K views 31 replies 15 participants last post by  SPHinTampa 
#1 · (Edited by Moderator)
I build high end longboards which use exotic veneer. I often run into a problem when using wild grain burls. The book match looks awesome when I vacuum press it onto the board, but then after I sand it the grain totally lightens up and I can't get it back. I've tried tung oil, shellac, high end polies, but it just doesn't do it justice… This last board I did, I told myself I just wasn't going to sand it, but there were so many mirco holes that the glue came through in the press so I had to sand it down. Completing this board was so anticlimactic because it looked better half way through than it did finished… Any suggestions would be greatly appreciated…

Here is the veneer during the bookmatch.
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Now after gluing it down and sanding and using tung oil and 3 coats of General finishes Enduro Var the grain is so faint its hard to make out any of the patterns. I resorted to using a paint marker to get the faces back, but it doesn't do it justice. I'm so ticked right now. I'm just glad I made this for myself and didn't try to sell this one, because it would be false advertising.

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Any suggestions would be greatly appreciated!
If you like my boards. Check out www.trlongboards.com
Thanks
Tom
 
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#2 ·
What grit are you sanding down to? Most exotics look best at 600+, and what wood is that, a lot of wood changes color or loose contrast when finished… hmmm.. and if you use Tung oil, some brands can give an unhealthy yellow tint making creams into other colors, but then I am partially color blind, but I notice tung oil tend to darken more than a natural finish danish oil. Both oil, in my opinion, don't always enhance the grain because they fill cell areas to catch light… and unusual grains can be dark.. or blotchy areas. But then I also feel that using a blotch control makes the wood look like plastic. Maybe you should forgo sand paper and use scraper cards. that will limit how much dust gets stuck in the oil as well.
 
#3 · (Edited by Moderator)
Vonhagen … Dude why are you still going after me. I did not contradict you in any way.. and if you look closer at my postings you will find there are projects with veneer, i do not post all the projects I have made. Try to be more professional and socially decent then trying to point out your inaccurate perception of my level of experience. Wingstress said exotic veneer.. walnut burl veneer is not really exotic, so I assumed it might have been something imported. Stop being a jerk and leave the drama in the non-shop forum where it belongs.
 
#4 · (Edited by Moderator)
Wingstress… yes Vonhagen has different experience than me, and His work is amazing… but there is a culture war going on here, and between us two in particular … and I apologize to you. Take my thoughts or not.. I work in all kinds of woods, not as many veneers, but I do finish most splotchy wood down to 600 when using danish oil.
 
#5 · (Edited by Moderator)
Wingstress - what glue are you using to vacuum press your veneers?

Often the lightening, especially burls which have so much end-grain will wick the glue as you are experiencing.
One way to avoid is to use 2 ply veneer since it will have less glue coming to the surface.

Some use epoxy, others a thickened PVA that has fibres in it as a thickener - so less weep
http://www.veneersystems.com/index.php/action/item/id/31/prevaction/category/previd/3/prevstart/0/

Good luck - the burl veneering I have done to make a radial match end-table I just used titebond white glue on walnut burl, and I didn't have a problem losing the grain (or at least not as dramatic as your longboard) and I finished with Waterlox original (tung oil wiping varnish).

Cheers
Dave
 
#6 · (Edited by Moderator)
I was going to post this after I got the poly finish, which will make the colors really POP.. but this is for you Vonhagen. Please let's try to get along on this site through some manner of respect and hate each other in private?

It is bloodwood veneer in laid with madagascar ebony, a reconstituted ebony veneer, on laminate italian poplar veneers, with a 1/8" steam bent walnut core.. the center is bloodwood stock, on poplar veneers with fiddle back Maple filaments and solid madagascar ebony anthers and stigma. I will have much better pictures showing details in a few days.

Wood Material property Comfort Beauty Hardwood


Dr Dirt.. :) I've been using a two part epoxy from WestSystem, one of the combinations fills open pores very well … and almost disappears under a varnish coat. If I get another order for a table like this I am most definitely switching to double ply veneers.
 

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#7 ·
I am having the same kind of problem with rotary cut bubinga. Unfortunately I do not have an answer for you but based on some research this weekend, I will offer a couple of theories:

1. burls are a lot of end grain, which will soak up more finish and tend to darken, reducing the contrast in your wood. The advice to finish to a very fine surface (essentially burnishing it) would seem to make sense as it would help keep the absorption rate of the finish more even.
2. the use of oil with a yellowish cast would tend to make brown appearing woods "browner" for lack of better term, again darkening your wood and reducing contrast
3. sanding (as well possibly pressure from the veneer press) tends to compress the wood fibers, which dulls down the chattoyance (sp?), so the use of the card scraper would shear away the compressed fiber, providing a more distinctive grain.

I plan to scrape the test pieces I have and try sanding with 400/600 on one half later this week to see if that helps. I am also going to test water based vs oil based finish to see if that makes a difference. I know that oil based finishes tend to make "figures" pop but I think this may be a case of too much of a good thing.

Again, I am not an expert, I am just reading what the experts say and trying to figure what to do. I will post my results.
 
#11 · (Edited by Moderator)
Ok folks, I dont do a ton of veneer, but i have finished alot of it, but I have some really good friends who are experts in it, in MHO, Sal Marino from http://www.monsterwoodshop.com/ as well as Randy Child, http://www.racfurniture.com/ , both are members here, so I am going to try to get them as well as myself to chime in here tomorrow, and see if we can answer all the questions, deal,,
 
#14 ·
Thanks everyone. So far, I've heard sand more, scrape, use different glue, and one interesting comment was the vacuum press pressing down the grain to mute it.

Because all my longboards are curved, I've never tried to use a scraper. Sanding more isn't a good option either, because my boards are expensive as it is. I really like the idea of end grain taking too much finish and "browning" out. I don't want to use different glue because I know the glue I use works in longboards. Many of my clients take my boards to 60MPH so I don't feel like experimenting with the construction.

Still feel stuck. :)
 
#15 ·
I could easily be smoking dope with regards to the use of a veneer press affecting the appearance of the wood. My thinking started when I noticed a difference in the appearance of the veneered surface after pressing it, which I do not recall seeing when I used the hot iron method for another project.

My reasoning is based on the fact that chatoyance is impacted by how light hits the fiber bundles on the wood surface. It stands to reason significant compression could change the configuration of large groups and disrupt the effect. A card scraper, or a gooseneck scraper for curved surfaces, should produce a better appearance if my thinking is correct.

I agree that it is more likely that something in the top coat is darkening the surface and eliminating the contrast.

Looking forward to hearing from Mr. Neil tomorrow.
 
#16 · (Edited by Moderator)
"did it ever occur to you that there are some **************************************** here on this website? ...you should think twice about what you talk about here. need i say more?"

Noooo, really? On this site? I never would have guessed… But at least we know that homophobia is alive and well around here. And I didn't even think twice about that statement. Should I be worried, vonhagen?
 
#17 ·
Can you guys find another forum to go fight on please. I've been a member of LJs for 3 years and have never seen such behavior on a thread. Vonhagen and epjarfagistan please to do not post on this thread again or any other that I create. Thank you
 
#19 ·
Interesting problem. It could be the veneer or the species, everyone seemed to have good responses to what it could be. In my opinion sand paper does this the second you touch it to the wood. The only way to solve this is to hand plane, or sharpen a scraper perfectly so it creates shavings, not dust, something thats much harder to do. When you take sand paper to the wood your tearing the fibers by running consecutively smaller rocks over it again and again until its hard to see the scratches, this dulls the grain. If you tune in your plane well with a high angle frog or a back bevel on the iron you can plane even burled veneer to a finished surface with no dulling of the grain. As far as doing this on a curved surface, idk but I love your longboards, sick idea.
 
#20 ·
Hi Wing, this is Sal Marino. A couple of questions if I may. Did you crossband or 2-ply this veneer? Does the veneer look just as good before you vacuum press it as it does after it's pressed, but before you sand? Can you send me a few close-up photos of before and after(s) (if you took them at higher resolution and still have those copies that would be ok).

Unfortunately my wife reminded me that we have an appraisal at 11:00 am today, so I may not be able to get back on, however I will respond when I receive your reply.
 
#21 · (Edited by Moderator)
OK..after reading the post. And all the offers of solutions..which I think are all great answers..and could be the solution to the problem..but will only know if tried..

There's a few things to consider when veneering..the thickness of the veneer..is the veneer raw veneer..meaning no backing..is the veneer wood backed..paper backed..and what glues or adhesive is being used? If you are using urea formaldehyde resin glue..are you using the brown..or white and regardless of which glue..how much glue is being spread..you want about the thickness of a good coat of paint..and..bleed-thru will cause changes in the figure and coloring..sanding with different grits will also contribute to color change and fading of figures if sanded too much..remember..raw wood veneer is usually 1/40" thick..after sanding..you might have 1/20" or even less..thus telegraphing the glue underneath..so that's a factor too..I have found that top coats of amber hues change appearances also..

One thing that I have learned to get into the habit of doing is running test samples using the same substrates and glues as my original and using the odd fall of the same veneers so everything is the same across the board..and test until I find the satisfactory results I'm seeking..
I think in this case..glue squeeze out..has changes the appearance..as well as the finish applied..
 
#22 · (Edited by Moderator)
Ok from a finish perspective, a knifed surface will yield a better pop of grain than a sanded, meaning give it a light scrape after you sand to bring the surface as clear as possible.
many like to use a oil and sand to make a slurry or gravy to fill grain and imperfections, and it works well, however it can also cause the fill to be darker, as well as the veneer, especially crotches.
the clearest finish I know of is a waterbase, , any oil, shellac and so forth are not always crystal clear, in addition, most oils and solvents have a reaction with the wood, thats why even a water white lacquer will bring up a ambering or darkening of the wood, its more of a reaction with the natural tannens in the wood
All of this said, to dring a grain back to life you have to fill the pores with a clear of some sort, thats why oils and so forth "pop" the grain, what they do is fill the pore and create a prizm effect to reflect light and add depth, any good clear finish will do the same, the waterbourne just will not add any additional color, as it is totally clear and has no reaction with the wood.
Any WB clear will enhance and bring the wood back to its natural color, without altering the natural color, if its too dark , you will have to look to either bleaching or reselecting the wood, in the above case, bubinga, will definately darken when any liquid is wiped on, to test for what it will look like simply wipe with some water, and what you see is what a WB will yield.
In the applications above we are looking to not alter the woods color, again a WB is the best bet, however, many do prefer the ambering effect of oils and shellacs, a cherry for example can look quite bland under a straight WB finish, a light coat of shellac or good quality oil can bring the color up a notch , I would have to caution on the use of BLO under WB , unless its completely cured, you can have adhesion issues, a simple solution is a coat of shellac,over the BLO after it has dried well , or better yet, just use the shellac, it will give the same pop and grain enhancement as the oil
Hope all of this offers some help and solutions if not ask away

One last thing, General Finishes Arm R Seal, is about as clear an oil as I know and can be topcoated with a WB after a good 24 hour cure . Just FYI
 
#23 ·
Thanks everyone for the indepth replies. The wood in this example is walnut burl, I've also seen the same thing happen to myrtle burl. See the "Peeping Tom" (When I glued it up is was so much more spectacular. You could see it from 10 feet away. When I was done you had to bring it up real close and squint)


The wood is raw veneer with no backing. The glue is Titebond III which is ideal for longboards because it is flexible when cured. There is some amount of glue squeezing through, but that can be expected on holey woods.

The veneer looks great coming out of the press. The second I hit it with sand paper its blured. I try wiping it with a dry tack cloth. I also use laquer thinner to look for any residual veneer tape. Often times on woods like bubinga, limba, cocobolo, a coat of shellac, tung oil, followed by a clear coat of a durable finish works fantastic. Its just when I get to the really wild grain woods (usually burl) that this seems to happen.

I would love to try scraping instead of sanding, but these things have 3D bends. The cross section accross the waist is in the shape of a "W". From tip to tail there is a large arc to absorb shock and transmit power in turns. Then on the nose and tail there can be up to a 1.25 inch drop to get your feet closer to the pivot point of the truck. Also, because most longboarders are broke, they aren't going to pay extra for me to sit there and sand to 600 grit. I have to use a ROS just for the time factor involved in making the board.

Thanks again for all your help.
For those interested in the boards, check out www.trlongboards.com
Tom
 
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