Good gloss on veneered dashboard advice

[Anonymous]

Have just veneered my son's tvr dashboard, one piece steal base and one glove box lid mdf, have applied several coats of sprayed acrylic gloss
but am not happy with finish, doesn't want to shine, any one got any idea's ?
Thought I might try several coats of cellulose varnish, but concerned
there maybe a reaction with the acrylic already applied

Any help would be greatly appreciated

Regards Pete

 

[Terry Smart]

Hi Pete

I wouldn't recommend applying cellulose over acrylic, chances are the solvents in the cellulose would strip the acrylic.

Can you give me some more information about the lacquer you've used. Is it our aerosol one? Some info on application and method would also be useful.

 

[Anonymous]

Hi Terry, thanks for the reply

I used .6 mm walnut burl veneer on steel backing (Existing) left in the warm to completly dry/ harden glue for a few days, then sprayed
HYCOTE clear lacquer acrylic formulation, (suitable for use with acrylic or cellulose paint) rubbing back between each coat, It's had about 6 coats to date
I now find on rubbing back an effect like small marbles in between veneer and sandpaper, not dust as I would expect.
acrylic seem to be the way of the future, but it's shine is definitely not as good
any suggestions Pete

 

[Philly]

Pete,
It sounds like the varnish hasn't totally dried yet. Wait a few more days before rubbing it out. If the finish is balling on the sandpaper its not dry. When you only get dust its ready!
cheers
Philly

 

[Anonymous]

Hi Philly

Bit concerned the last coat was applied last sunday ! so it's had 7 days in the warm

I suppose it could be the total of 6 coats together taking time to dry ?

Will leave in the house until next weekend before trying again

Regards Pete

 

[Philly]

Yeah, good idea.
Rule of thumb-if it doesn't sand into dust, it's not ready to rub-out. It may be "dry", but it isn't "cured".
I'm no expert, but have had the same problem!
cheers
Philly

 

[Terry Smart]

Hi again Pete and Philly

I'd tend to agree that the material isn't quite dry yet, although after that period of time it should be. I'd worry about the last coat (or two) being a little thicker than inteneded, which can cause a lacquer to surface dry but remain 'wet' (probably a very firm gel-type consistency) so that when rubbing back the top surface is broken and the friction causes the marbling effect.

Allowing more time could well assist the drying process but it may require quite a lot of time as the lacquer now cannot air dry as it would like to.

My next question would be whether you have tried a polishing compound of any type over the lacquer? Something like our Burnishing Cream or possibly even T-Cut (although that can be a bit too harsh) to improve the finish? It can be a great shortcut to a brighter finish.. although it will require some elbow grease!

Let us know the progress!

 

[Chris Knight]

Pete,

Your lacquer should be dry by now - it normally dries very quickly - so it may have been on the shelf too long if indeed it is still not dry. However, I reckon Terry is right and a thick coat went on.

Walnut is an open grained wood and for a really glossy finish it needs to be grain filled. My preferred filler for walnut is an oil-based filler (I use Bollom's). Don't confuse a grain filler with the sort of woodstopping you see called a filler sometimes - it's a very different animal.

I would on no account try to polish the lacquer with a burnishing cream at this stage. If the finish has not properly filled the grain, any lack of film integrity is going to trap particles of white cream/polishing debris under the grain and under the film - it is damn nearly impossible to correct this.

Personally, I would sharpen a couple of cabinet scrapers and remove the finish completely. Fill the grain and start over.

 

[Terry Smart]

Hi Chris

Good comments, thanks; I'd assumed that the preparation work had been carried out and that after six coats the surface of the lacquer would form a sufficient barrier to prevent the situation you describe, although I'd be interested to hear if you have experience to the contrary.

I'm tending to agree with having to strip the whole lot off, but if it is possible to save the job without it it would be a bonus!

 

[Woodythepecker]

I tend to agree with Philly that it has not fully dried yet. I know that it may sound like a silly question but are you sure that mixed the acrylic properly?

I am no expert but i have restored a few cars as a hobby and i had exactly the same problem a couple of years ago with the dash on a MK2 Jag. I was pulling my hair out before i realised what the problem was. Granted i was using a 2 part self leveling finish but the problem might still be the same.

Good luck and i hope you get it sorted.

Regards

Woody

 

[Chris Knight]

Hi Chris

I'd assumed that the preparation work had been carried out and that after six coats the surface of the lacquer would form a sufficient barrier to prevent the situation you describe, although I'd be interested to hear if you have experience to the contrary

Terry,

I have had problems when using finishes that don't dissolve into prior coats as say shellac or nitrocellulose do. When using finishes that create distinct layers I have found that if one sands through a layer or two when flatting a coat, then come burnishing time, it is possible for the cream etc. to get between the layers forming an unwelcome bloom. If pinholes or sanding flaws go all the way to the bare wood, then one can get the stuff in the grain and that is tear the hair time. It is inevitably easier to do this at edges where sanding can all too easily go further than intended.

Pete didn't talk about his preparation so I don't really know how much, if any other than a sanding job, he did. Of course, sufficient coats of a finish, properly flattened between coats will eventually fill the grain - it just takes longer than a proprietary grain filler. I also find it educational to check just how much a finish can sink into grain after it has apparently dried. Examined under a strong raking light a couple of days apart an initially nice finish can look quite rough at the second viewing.

I think burl walnut is likely to compound the problem as by its nature there will be a fair bit of end grain there.

 

[Anonymous]

HI Pete

I think that I would have to agree with the others that the previous and/or last coat went to too thick to fully cure. I have had this before with paint.

I suspect that the best option is Chris's suggestion of using a scraper back to the wood and start again

 

[Anonymous]

Well, what can I say but thanks to everyone who has commented on my problem.

I started with sanding the veneer, not using a filler, then applying light coats and sanding quite hard removing most of the coat, using the varnish as a filler. The veneer has a leather look and with a good shine would have looked great, my intention was just to keep building up layers until the finish I wanted was just right, sanding back between coats. At the moment I am using 400 grit, the grit grade getting higher as the coats were applied.
From my days on motorbikes and old cars we often used T cut and Brasso before final polishing
One point which rang true was the thickness of coats, coats 5 and six were quite thick, and I assumed the varnish would just take a little longer to dry, like cellulose
My problem is atmospheric damp being a sports car and not used on a regular basis,
I was worried about using cellulose varnish on wood, maybe I should have used a poly varnish but was worried about the brush marks removal
Stripping looks a good option, but as it's winter I thought I would leave the varnish in the warm until the weekend, try a sanding, if it's the same then strip and start again.

regards to all Pete

 

[Anonymous]

2p....

I have had a lot of success finishing varnishes and lacquer with extremely fine steel wool. My desk (on which this computer sits) is hard maple with 5 coats of varnish rubbed down to a finish with steel wool and finally buffed with hard wax. It gleams! Have to make sure EVERY bit of steel dust is removed between coats -- and if the finish isn't fully cured it's a strip and start again job.