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Pachoud Boat yachts infuse 54 foot monohull

(continued from page 1) The mold was infused in May. Following that the hull itself was successfully infused early June. Both of these large molds, upward of 200m
2 (2150ft
2 ) film area, were bagged using a single Vacmobile 20/2 machine. However, as we always recommend, a standby unit was plumbed in prior to each infusion as backup. Pachoud Yachts has gained valuable infusion expertise and confidence over these last few months and are looking forward to a bright future with an increased utilisation of vacuum processes. For more information contact: Pachoud Yachts +64 7 578 8252 www.pachoud.co.nz High Modulus NZ Ltd +64 9 415 6262 www.high-modulus.com Adhesive Technologies Ltd +64 9 838 6961 www.adhesivetechnologies.co.nz

Vacman’s technical tips

(continued from page 1) Improve part evacuation via additional Improve part evacuation via additional Improve part evacuation via additional Improve part evacuation via additional vacuum line from a ‘T’ on the marine resin feed.vacuum line from a ‘T’ on the resin feed.vacuum line from a ‘T’ on the resin feed.vacuum line from a ‘T’ on the resin feed. Typically the resin feed side of a part is the most permeable region of the lay-up. This is because it is normally desirable for the resin to flow into the part easily. If it is easy for resin to flow into the part, it will be easy to take air out by the same route. Conversely, the perimeter of the part is usually provided with a resin break to make it difficult for resin to flow out of the part. If it is difficult for resin to flow through the resin break, the flow of air will also be impeded. While still sensible to have a vacuum line around the perimeter of the part to overcome air leakage into the bag for boat during infusion, the logical way to remove air from the dry-stack
after the part has been infused. When the part is full, close the valve under the resin bucket and open the resin feed vacuum line again. Applying vacuum to the resin feed line will withdraw excess resin from what is often a resin rich region of the part. Valves around the vacuum perimeterValves around the vacuum perimeterValves around the vacuum perimeterValves around the vacuum perimeter ( see illustration on page 5). If air is evacuated from the dry stack via the resin feed line(s) as suggested above, the perimeter vacuum line only needs to handle a limited air flow during the infusion (from air leakage and air entrained in the resin). To make the perimeter vacuum line work well, we recommend placing a Feeding resin from the bottom of the Feeding resin from the bottom of the Feeding resin from the bottom of the Feeding resin from the bottom of the resin supply bucket or drum.resin supply bucket or drum.resin supply bucket or drum.resin supply bucket or drum. If not using a continuous resin feed system, resin is usually batch fed from a bucket or resin drum. The resin feed tube(s) are normally inserted into the resin bucket from above. Feeding resin from the
consistent width resin break of peel ply between the edge of the dry stack and the perimeter vacuum line. A peel ply break of about 30 to
bottom of the resin feed container, via a bulkhead fitting and a valve, is a much more controllable and safer solution. Bottom feeding via a valve provides a more secure feed line than the usually improvised top feed method. Bottom feeding also greatly reduces the risk of air inadvertently getting into the part when feed lines are changed to a new bucket, or the bucket is refilled. The valve under the resin feed bucket allows complete control of resin flow. Resin flow can be throttled if flowing too fast for thorough wet- out, or stopped completely while a new resin batch is mixed and added to the bucket. Towards the end of the infusion, resin can be mixed and added to the resin feed bucket in smaller batches with complete safety, reducing resin wastage to the minimum. While a low cost enhancement, feeding resin through the bottom of the bucket via a valve works very well! 50 mm (1 ¼” to 2 ”) between the edge of the dry stack and the perimeter vacuum line seems to work well. If using spiral wrap as the perimeter vacuum line under the bag, a 150 mm (6”) width of peel ply folded over the spiral wrap will be a suitable resin break.
prior to infusion is via the resin feed lines. This is made possible by placing a valve under the resin feed bucket and a ‘T’ (with a further valve) on the resin line. This ‘T’ connects to a vacuum line to the resin trap. To evacuate the dry stack through the resin feed vacuum line, close the valve under the resin feed bucket and open the valve on the vacuum side of the ‘T’. Once the part has been evacuated, close the valve on the vacuum line. After filling the resin bucket, open the valve under the resin bucket to admit resin to the part. There’s another use for the additional vacuum line
Continued page 5...