Varnish of difficult surfaces
In the surface topcoats you must take into account always the support, issue that in the major of occasions we can´t decide, it comes imposed. Especial difficulty presents wood stain varnishing and especially tropical woods (solid and sheeting) like rosewood, paloleo, etimoe, iroko, etc. to closed pore. Especially if polyester is going to be used for filling as sealer.
Solution to varnishing this difficult surfaces, is found isolated of themselves, through a primer which, closing surface, will continue allowing follow normal processes without damages. Valresa has a exclusive polyurethane primer of two components named VALPON I Ref. 110015 which is hardened 100% (equal parts) with polyurethane hardener Valpon E Ref. 190021 for wood and sheeting of normal colors or Valpon E NAM Ref. 190046 when you want to manage a yellowing absence.
This polyurethne primer is very liquid, it´s gun application doesn´t require thick layers and allows, once dryed, produchs applied over it don´t enter in contact with surface treated, and at the same time have an excellent adherence. You just have to observe simple precautions, as they are giving fine primer layers (don´t overload in excess), leave it dry during a minimum of 24 hours and before continuing topcoat process, move slightly a medium grain sand (from 240 to 320), without pushing down.
The most outstanding recommendation, as indicated before, is for wood and sheeting with lots of resin, when over them we must apply polyster varnish or transparency polyacrylic varnish. Especially due to utilization of this primer adequately and the use of our products named VALPON F, guarantee us the absence of bleaches and veiled after long period of time and in environments very hostile.
But also gives excellent results when we dream to fill the pore of difficult woods (Lupa, Palm Mahogany, Bubinga, etc.) with transparency polyurethane sealers, as it allows us saving in sealer material and manage a totally cleaned aspect, withouth veiled neither azuleos, even in dark tones. Equally it is very advisable for lacquered, especially when we wish to carry out studies for sheetings or about MDF of uncertain quality. In the first case avoids the aparition of holes and reduces the quantity of sealer and sanding to apply. With the MDF the utilization of primer apart from reducing the quantity of sealer applied, guarantees, excellent adherence over machined surfaces and danger (inhibition of sealer dry, poor attachment, sink marks, etc.) of certain boards, for being manufactured with wood wastes.
We have displayed in our development laboratories that this primer applied directly over the MDF or DM waterproof the support in a considerably way preventing water absorption, by direct contact or by high relative humidity. We will avoid swelling of DM or laminated wood, as well as the take off of sheeting from our kitchen, bathroom or outdoor furniture. Advisable it´s application over DM doors, baseboards and moldings.
At last we will stand out the security which this primer provides us when we should finish surfaces which have had previous treatments, which we unknow it´s nature and previous behaviour.