Join Date: Jul 2000
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I have a Ty37 and can empathize. Ive been using HT for almost 14 years, I usually get 10+ years out of HT before I need to 're-do'. I double coat with clear every 2 years, and power buff with 2000 or 3000 grit compound in the intervening years (Im a reformed varnish-a-holic, so I cant help myself).
•The colder the ambient temp, the HT components and the wood temp., the better the flow-out. I even keep ALL the components in the refrig. when Im looking for 'flow'. This is for 'horizontals' such as caprails and thin eyebrows, etc. If the wood is HOT, I wont apply HT to the 'horizontals' to avoid 'brushmarks, etc.'.
• Slightly LESS catalyst and more 'flow fluid' but *thin coats* on the VERTICALS - will allow a quicker 'kick' without sags and runs. 2 thin coats would equal to 1 normal coat.
If runs sags after all base coats applied, I wet-sand to 'just flat' then apply one more thin base coat coat --- Tom Fabula and I argue about 'my lay-up schedule' all the time ---- but I want a FLAT perfect job without any hints of runs or sags.
High learning curve on 'verticals' with HT to prevent runs/sags. Best to do the verticals on a very WARM, low humidity day, with LOTS of wind, using 'thin' coats, - single coats.
• To also prevent runs/sags on verticals - ONE COAT PER DAY. Allow coat to full cure before applying next coat .... if not full cured, the second coat will sometimes soften, etc. the first coat ... and enhance runs/sags on verticals. I mean long verticals, not the vertical edges of caprail, or eyebrows, etc.
• Additional help to prevent runs sags on verticals ..... LOW humidity, and LOTS of moving air across the surfaces - will accelerate the evaporation and quicken the 'kick' of the catalyst. Sometimes I'll put a FAN to the work area if not enough wind is blowing.
• MORE catalyst to allow better flow out on horizontal surfaces. For large area horizontal surfaces finish coat, I use PreVal self-contained sprayers and HT clear and with extra catalyst to enhance the flow-out.
• HEAVY wet coats on the horizontals, the thicker the better. For better fill and better flow.
Other hints - (applies to just about all similar coatings) apply when temp is rising and dewpoint is dropping. Certainly NOT at near the end of the day when just the opposite conditions are occurring .... unless you want a 'satin' finish.
For longevity vs. Sun/UV I lay down THREE *thick* base coats (5-6 'thin' coats on the verticals).... Tom Fabula still insists two are good enough, my HT applications usually last 10 yrs. before I have to start removal/restoration. For me, the heavier the base coat, the longer lasting vs. UV damage.
Of course, scarfs, plugs and any other joint that moisture can come up through will always be a problem for ANY coating system ---- the 'blacks'. Good idea to first use a penetrating epoxy on the 'joins' to help seal and prevent the moisture bleed.
That TENT you're under has to be well vented and air blowing through or the humidity may become much too HIGH and will then create a LONGER or much extended evaporation and 'kick' time. BIG fans might help, so may putting plastic tarps over the bare ground. Ive found that I cant use HT even for small stuff inside a garage ... the evap and kick time because of the high humidity is just waaaay too long. In a garage I have to only coat the horizontals, let cure, rotate the next portion to horizontal, etc. or sags become a problem .... probably due to the high humidity you get in enclosed spaces. Varnish is affected in the same way.
Other: If you used ANY chemical stripper to prepare the wood. You must be SURE that all of this is completely off-gassed out of the wood or you will get 'grain-print-through' all the way into the final coating !!!!!! Most burmese type teak like yours (and mine) seems to absorb MEK, etc. into the soft grain and not the the harder dry season grain. If you used any stripper, contact Tom Fabula to discuss the best method of MEK, etc. EXTRACTION from the wood. Sometimes it take MONTHS for the stripper carriers to completely off-gas and not 'print-through' into the surface coating .... you wont see the print-through immediately as it can sometimes take months (after coating) to show up. No print-through will occur if you didnt use a chemical stripper.
Last edited by RichH; 07-12-2010 at 09:16 PM.