Sanding Alder Veneer Plywood

[SGCrain]

Hi All

I posted about this already on the 'Festool how to' section but haven't gotten a lot of response so I thought I would try here to see if I get more action. I've done some experiments since then and are still having trouble. Here is what I'm trying to do:

I'm sanding 2 kitchen's worth of alder veneered plywood cabinet doors and staining them dark brown. I have tried the following:

1. Borrowed an rts400 with Brilliant2 120g and 180g. Didn't have any 150g. The result was pretty darn good. The grain was clear.
    There were some evident swirl marks but I assume that was because I had to skip from 120g to 180g.
2. Borrowed an RO125 again with Brilliant2 120g and 180g in RO mode. Didn't have 150g. The result wasn't as good but still not     
    bad considering.
3. Bought an ETS125. My supplier didn't have any Brilliant so I bough Granat 120g-150g-180g. The sander was set on high speed
    (6) and the vacuum was set on low. One of the techs at Festool told me this was the best setting for what I was trying to do
    and that Granat paper was the way to go. I did some samples sanding 120-150-180 and stained them and it's just a hot mess!
    Very muddy, lots of swirl marks and 'tracks' like grit is getting stuck between the sandpaper and veneer.

This is a very large job we are about to do and I need to find a solution quick! Any advice would be so greatly appreciated! [crying]

Thanks.

 

[junk731]

IMHO the ETS 125 is not the sander you want, go for the ETS 150 3 which is 10 times the sander. One of the major problems with the ETS 125 is you can get the suction low enough to have the sander operate properly unless your vac bag is plugged or you put a Y with a gate valve to lower the suction even more. This also occurs with the RTS 400 to some extent also especially with a fresh bag. There are multiple posts about the pro/cons of the ETS 125/ RO125 shortcomings, whether you choose to believe the short comings is up to you. I owned and tried to use both, they both gone and I use the RO 150, ETS 150 5 and ETS 150 3 daily.

John

 

[tiralie]

I'm sanding 2 kitchen's worth of alder veneered plywood cabinet doors and staining them dark brown. I have tried the following:

If you really need to sand the alder I would use a RO 150 and 120-150 in Rotex mode.
Just curious, have you done finish samples after the sanding tests?

What's your finish schedule so far?
Are you using waterbourne or solvent based finish?
Tim

 

[jbasen]

I'm using one of these Bosch adapters to further lower the suction when sanding since the Festool adatper for lowering the suction is NAINA.

http://www.amazon.com/gp/product/B00HUCUNGC/ref=oh_aui_detailpage_o05_s00?ie=UTF8&psc=1

 

[tjbnwi]

Wrong sander, you need the Rotex in aggressive mode.

I'd sand 180 only see how it looked. If I had to go coarser, 150 then 180.

Using the Festool blast gate on the CT is a great way to bleed off vacuum.

Last year we did 200 sheets of mahogany veneer, never used anything coarser then 180 Granat. Rotex, aggressive mode, speed 4. Between finish coats was 320 on the ETS 125.

Tom

 

[SGCrain]

Well I just tried my buddy's RO125 in ROTEX mode w/ 150g & 180g Granat on Alder plywood and stained with old masters spanish oak wiping stain as I have done with all the others and you see lots of definite swirl marks. I then tried just 180g but still the same. I then tried a piece of mahogany plywood with 180g with the same results. I would also say that I can't imagine sanding a boat load of veneered cabinet doors with a Rotex. It is hard to control. I tried holding it mainly by the back end with just my other hand lightly resting above the sanding pad but but it still kicks and jerks and has a mind of it's own. Not sure how you guys do it! I think I'll take my ETS125 back and try the ETS150/3 next. I still wonder about the Granat paper because I got an almost acceptable result with the RTS400 with Brilliant2 120g and 180g. Again I assumed the swirl marks was because I skipped a grit. Hmmmm. Back to the drawing board.
In answer to Tim's question I am just putting stain on the panels after I sand. I am not spraying lacquer on them. We will be spraying ML Campbell Magnamax precat lacquer when we do the actual job.

 

[tiralie]

Well I just tried my buddy's RO125 in ROTEX mode w/ 150g & 180g Granat on Alder plywood and stained with old masters spanish oak wiping stain as I have done with all the others and you see lots of definite swirl marks. I then tried just 180g but still the same. I then tried a piece of mahogany plywood with 180g with the same results.

Not sure what to say. I don't get swirl marks sanding in Rotex mode, well I do if I put too much pressure on the sander but other wise no real problem.

I would also say that I can't imagine sanding a boat load of veneered cabinet doors with a Rotex. It is hard to control. I tried holding it mainly by the back end with just my other hand lightly resting above the sanding pad but but it still kicks and jerks and has a mind of it's own. Not sure how you guys do it! I think I'll take my ETS125 back and try the ETS150/3 next.

The ETS 150/3 is a very nice sander particularly for large surfaces.

I still wonder about the Granat paper because I got an almost acceptable result with the RTS400 with Brilliant2 120g and 180g. Again I assumed the swirl marks was because I skipped a grit.

I don't think it's because you skipped a grit. The RTS is a great sander but tippy, so you gotta go slow and easy.

In answer to Tim's question I am just putting stain on the panels after I sand. I am not spraying lacquer on them. We will be spraying ML Campbell Magnamax precat lacquer when we do the actual job.

I would test the whole recipe without sanding the panel, sand between lacquer coats and see if you like the overall finish quality. Unless the Alder is really rough, (it could be) you may be able to sand out any minor nibs etc.
Tim

 

[SGCrain]

I thought I would report back with my results so far. As I've said before I've tried the Rotex 125, the RTS400, the ETS125, the LS130 just cuz,  and now the ETS150/3. I've tried the Granat paper with many different grit variations, some with just 180 only. I've tried wetting the wood first as well. I have about 22 samples so far and I'd have to say the best 3 are:

ETS150/3 -180g & 220g
ETS150/3- 180g only
ETS150/3-wet the wood then 180g only

The ETS150/3 is as everybody says a very nice sander to hold and operate. The 6" pad is wonderful for medium to larger flat surfaces. The only one I haven't tried is the RS2E which I assume would be like a large RTS400. I get good results with the RTS but the ETS150/3 seems a little better as far as swirl marks, etc. My next step is to shoot a clear coat or two on these and see how they look. I'm sure the fact that I'm using Alder veneer and that I'm staining it dark are making things much more difficult. If this were Walnut or Oak veneer or solid wood for that matter I'm sure some of these other sanders would have been just fine. I'd have to say that I'm surprised Tom had such good results using the Rotex on 200 sheets of mahogany ply. Tom-were the panels stained or just clear coated? I know a dark stain will magnify any imperfection in the wood so that is really working against me. I wish I had the time and resources to test other sandpapers besides the Granat to see what difference they make. My local suppliers seem to stock Granat mostly. Anyway. I will post again after I have sprayed my samples. Thanks for everybody's time and valuable advice.

Steve