Bassett UV Cured finishes now appear on dining tabletops and soon will be on the office groups as well. It is important to have procedures in place to work with this type of finish in the field. The purpose of this document is to give the technician the best method and products that are available at this time to deal with this very durable finish, should it become damaged. In essence, this finish is no more difficult to repair than any other type with the correct products to replace the sheen and using Polyester abrasive procedures.
These finishes consist of a three-part system to build the film. The first is a catalyzed vinyl sealer. The second is a three-step roll coat procedure using 100% solids UV Cured Urethane Acrylic. The third is machine sprayed 4 to 4 1/2 mil wet coat of 40% solids UV Cured Polyester producing a dry film of about 1.65 mils. With this film, it appears that the flatting agents used to bring the sheen down to 25 to 30 are assembled just under the top skin of the topcoat. Light sanding will produce a very flat look quickly by cutting through this skin. Light polishing will produce a high sheen quickly as well by polishing this skin. Consequently, sanding and rubbing procedures are out of the question as a means of small damage repair. Any and all repairs must be finished up with a coating that will match in sheen, have great adhesion and lay down a very thin edge. A small amount of finesse work will remove the over spray.
Most all of the repair procedures normally used in the business could be used on this finish, Burn-In, Graining and Color Work. However it is necessary to follow a few rules normally used on Polyester. First, damage to a polyester film will normally leave a white line where the damaged has occurred. Filling over this will usually not make it disappear. This can be removed with a Pro-Marker applied right down into the damaged area. Wipe the top of the area with a rag and solvent (lacquer thinner, Acetone or CA glue solvent) to remove all color from the top surface leaving color down in the damaged area only. Next, if the area needs to be filled, burn-in with either of the Mohawk burn-in sticks. Level well and sand the area flat. Use liquid wol-wax mixed 75% water as a lubricant for this and all other abrasive procedures. The abrasive can be a 1000 grit or higher wet or dry paper or 2400 grit micro abrasive. Use strips ½ to 3/4 of an inch wide wrapped around a cork or rubber block to keep better control of the area. It is important to keep the area very wet during this operation. Use one hand to sand the area (keep it small) and the other to constantly feel the progress that is being made. Dry frequently to check visually. In the case of a very minor scuff, sanding sealer can be sprayed and wet sanded to fill the defect. Use Mohawk # 102-0413 or 102-0484 Sanding Sealer.
After the area is smooth and flat apply the E-Z Seal pen and feather the edges well over the burn-in. If any color adjustments or graining is needed, do it now. Next, spray two soft dry shots of sealer and one medium wet shot over the area that has been sanded and allow each shot to flash. Try not to exceed the sanded area and shoot from straight down on the spot to help feather the edges. Dry well and use the same sanding procedure previously described until you can’t feel the area. Dry the area well and apply the topcoat. The topcoat material is a Pre-Cat dead flat Mohawk number 102-0414. Apply the product in a similar way as the sealer, allowing the edge to extend out past the sealer edge. When dry, there could be a slight rough edge that
can be removed with a fine abrasive pad and very light pressure using the same rubbing lube previously described.
Use Very Light Hand Pressure on all rubbing procedures on this product. Rub with the abrasive pad very briefly and then go to a dry cloth and rub the area dry until smooth. Gloss can be brought up slightly over the repaired area with this dry cloth- procedure if needed. When finished, view the spot from 360 degrees, at 20-40 degrees of angle to determine if the texture is right. If the area appears to be smoother than the rest of the top, dry spray to create texture to match. Use the dry rag procedure to remove the over-spray when the finish is very dry.
You will probably find that the lighter finishes are less difficult to work with than the darker ones. The spot seems to hide better on the lighter finishes. Other minor repairs not involving the top can be repaired with fil-sticks and touch-up markers just like any other finish.
It should be noted, the Pre-Catalyzed repair material is a very durable material in and of itself. However, it is not as solvent resistant as the original UV Cured finish. In most situations, it will be more than adequate for normal uses.
Mohawk Materials Needed to
Make Repairs
1. Burn In Sticks, assorted colors. Mohawk # 350-3600-Plane Stick or # 316-6000 EZ Flow assortment.
2. Fil-Sticks, assorted colors. Mohawk # 230-5200 assortment
3. Graining Pens. Mohawk # 265-0501-Black, 265-0301-Med Brown, 265-0401 Dark Brown, 265-0101-Light Oak.
4. Touch-Up Markers 298 series for edges and 267 series for damaged areas on Tops. 298-2400 or 267-2670 for assortment
5. Rubber Block, Mohawk # 902-3000 or Cork Block # 902-2000
6. Burn In Balm, Mohawk # 401-1203
7. Wol-Wax Liquid Mohawk #720-1365
8. Empty Squeeze Bottle, To mix wol-wax and water Mohawk # 983-1004
9. Abrasives, 1200-Wet or Dry #906-8012, 1500-Wet of Dry # 906-8022 and Micro Mesh 2400 #905-0241.
10. Abrasive Pad- Gray (fine) #910-7412 and White (very fine) # 910-7414.
11. Sanding Sealer, Flat easy sand # 102-0484 or Pre Cat # 102-0413.
12. Topcoat, Pre-Cat Dead Flat # 102-0414
13. EZ Seal Pen, to seal burn in. # 295-0001
14. De-bonder-to remove pro marker from top surface #745-1001
15. Cloth, soft cotton # 904-1001
Application Notes from the Lab
The procedures described in this document were conducted in two ways. First, test was conducted in a controlled environment and second in an un-controlled environment.
The controlled environment was at 72-74 degrees with 55% humidity and no air drafting. In that environment the procedure worked well. In the un-controlled environment, 68-70 degrees at 75% humidity and a slight draft, the results were of less quality.
An explanation can be offered for these differing results, but a suitable alternative could not be found. Most finishers know that in differing temperature and humidity and adding air movement will cause the finish to dry at slower or faster speeds. In most cases this is not a problem, however with a touch-up or spot sprayed on a tabletop, it becomes a large issue. The very small amount of moisture that can become trapped under the finish will cause a very slight hazing and that is enough to make the spot very visible. Keeping the finish perfectly clear is very important. Although there are several ways to remove blush, in this application it is not acceptable. Post application Blush Removers do not work well with Pre-Catalyzed finishes. If they work at all they distort the surface and make the spot noticeable. Pre-Application Blush formulations will slow down the finish drying and allow the finish to lie more flat than the surrounding areas and thus become more noticeable. It would also take away the ability to texture the finish somewhat additionally as mentioned in the procedure by staying wet longer and laying down more flat. In addition, Pre-Application Blush removers would stay wet to long and damage any repairs that were made under the film. Such as burn-ins, color work and the like.
Given these negative aspects of re-formulating the topcoat materials, it is determined that the lesser of the evils is to deal with the conditions and change them if necessary. If the table is in a warehouse and must be repaired, move it to a controlled environment of wait for better conditions. In stores and homes this will probably not be a problem since most of those areas are controlled environments. Th