blotching in hydrocote finish

[Len]

I have been trying to finish a couple or doors. Something went wrong in th e finish product (I think). Can anybody spot my mistake so I can complete the job? I should add that this technique worked flawlessly on a previous set of doors.

This pair of doors has a (very expensive) molded glass center. So I am fin ishing only the frame surround, which is a set of 2x6,1-1/2 thick. I do no t wish the strong grain to adsorb color and become dominant.

The main colorant is a toner that I made: It is Hydrocote lacquer colored with a premixed water borne dye. The dye was mixed first, cooled, and then poured into the lacquer. The mixture seems to be uniform in color.

My spray sequence was

1) Spray the door with a coat of Bullseye shellac and, after drying, I lightly sanded it smooth. The idea of the shellac was to prevent the grain from becoming too strong in the final product. 2) I then sprayed the water borne lacquer toner on top.

3) If nothing went wrong I would then spray a couple of coats of clear Hydrocote and rub out the finish.

I have used this technique before with excellent results. However, this ti me the result was a blotchy mess. At first I thought it was fisheye. But, after drying, it appears to be smooth. but blotchy. The color is not unif orm - even thought the toner seems to be uniform in color and consistency.

Should I:

1) just keep spraying hoping that it will become uniform with increas ed colorant or should I stop and strip it. 2) add more color to the hydrocote 3) try to make a dye mix with significantly less water and add that to a new batch of Hydrocote. 4) strip it and try a whole new approach.

Len

[Rick the antique guy]

the finish product (I think). Can anybody spot my mistake so I can complet e the job? I should add that this technique worked flawlessly on a previou s set of doors.

inishing only the frame surround, which is a set of 2x6,1-1/2 thick. I do not wish the strong grain to adsorb color and become dominant.

d with a premixed water borne dye. The dye was mixed first, cooled, and th en poured into the lacquer. The mixture seems to be uniform in color.

time the result was a blotchy mess. At first I thought it was fisheye. Bu t, after drying, it appears to be smooth. but blotchy. The color is not un iform - even thought the toner seems to be uniform in color and consistency .

Just a quess Did You fine sand your shellac 220 -320 grit ? This creates a better surface an etch for the finish applied over it. Next Temperature and Humidity can be problematic moisture on shellac will j ust sit there like condensation . Make sure it is wiped dry prior to your topcoat of water soluble or solve nt based topcoat. Stripping or scraping it off may be your best alternative. if it were solvent based You could use acetone or Laq. thinner to remove it down to the shellac but since it's water base this stuff is hard to deal w ith when dry. If it's not too thick You could try sanding it until your col or seems uniform again but that is a crap-shoot. Having not seen the piece it's hard for me to determine the problem But I am going to guess it's a blushing layer of moisture between shellac a nd topcoat. Or possibly too thick ,too quick on Your topcoat

After agonizing over similar problems in trying to repair such a mess. I now resort to stripping and starting over in order not spend a lot of ti me correcting an inferior finish.

That's all I can come up with for You I hope i have shed some light on Your problem.

[Rick the antique guy]

n the finish product (I think). Can anybody spot my mistake so I can compl ete the job? I should add that this technique worked flawlessly on a previ ous set of doors.

finishing only the frame surround, which is a set of 2x6,1-1/2 thick. I d o not wish the strong grain to adsorb color and become dominant.

red with a premixed water borne dye. The dye was mixed first, cooled, and then poured into the lacquer. The mixture seems to be uniform in color.

s time the result was a blotchy mess. At first I thought it was fisheye. But, after drying, it appears to be smooth. but blotchy. The color is not uniform - even thought the toner seems to be uniform in color and consisten cy.

just sit there like condensation .

vent based topcoat.

it down to the shellac but since it's water base this stuff is hard to deal with when dry. If it's not too thick You could try sanding it until your c olor seems uniform again but that is a crap-shoot.

and topcoat. Or possibly too thick ,too quick on Your topcoat

time correcting an inferior finish.

Another fine point is: that I rarely color or stain topcoats other than f or a repair or touch-up to an existing finish.Sometime if the finish is no t subject to wearit is an acceptable choice to darkenor change color hue sl ightly. It's almost a certain disaster when tryiing to go to a lighter shade.

I always prefer to stain or color the wood itself prior to the sealing with a shellac or sealer. This adds depth to the color and it is less likely to chip scrape or scrat ch off as it would if it were a colored topcoat. In most cases let your topcoat be clear not mixed with colors or stains. It's more easily ready for a scratch repair,since you may not have damaged the color beneath the sealer rick B.

[OFWW]

With some woods this is vital to prevent blotching. Did you over sand the sealing coat? Was it too thin?

In the back of my mind I sort of remember doing a "water absorption test" after this step in order to verify an adequate coat.

However, bear in mind that my experience is limited here.