Bow bumper - custom design

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Bow bumper - custom design. Cast in your mould from silicone rubber. Send us your own mould and we will make the bumper from it. Please select colour from the drop down menu.

Product code. 330-CUSTOM

Availability: In stock


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Bow bumper - custom design

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Bow bumper - custom design. Cast in your mould from silicone rubber. Send us your own mould and we will make the bumper from it. Please select boat class and bumper colour from the drop down menu.

Q. What is the best way to make a mould for a bow bumper?

A. Shape a pattern of the bumper you want using balsa, obechi or other easily worked material. Finish the surface to a smooth surface using cellulose primer and mount the pattern onto a smooth, flat surface (glass, plexiglass, plastic sheet etc) using double sided tape and coat the pattern and surrounding surface with a release wax that you are familiar with. Simoniz works well if you do not have any other mould polish at hand. Apply several coats and allow time for it to harden between each coat. Construct a box to surround the bumper 40 mm wider and longer and 10 mm deeper than the pattern itself. Find a way to hold the box down to the surface (double sided tape, weights etc).

The quick and inexpensive way to make the mould is to full the box with plaster of paris or some similar material. The surface finish will be poor, the sharp edges will probably crack off when the pattern is removed and the subsequent bumper mouldings will have every shortcoming faithfully replicated in its surface.

A better way is to use Plastic Padding or similar polyester filler. Make sure it is a fresh batch or it will not be fluid enough to flow into the sharp corners. It is best to mix a small amount first and apply that thinly over the pattern surface than to try to mix a larger batch and pour it in.

An even better way is to use polyester or epoxy gel coat followed by layers of thin woven glass backed up by heavier reinforcement. A laminate like this will be easier to de-mould than the cast versions.

Q. What is the best way to add a silicone bow bumper boat?

A. The only material we have found that will bond the bumper is silicone sealant as for sealing around work surfaces, pipes and tiles.

The correct one to use is the one that smells strongly of acetic acid (vinegar). No other types will work. Choose the clear version. The one we have in the workshop is a B&Q product labelled ‘translucent all purpose, waterproof, flexible, mould resistant’. The instructions/data printed on the package indicate it gives off acetic acid when curing. Buy the 310 ml size if you need a large quantity. Alan Bright advises another option is product code S57100 from stix2 - UK customers can obtain small tubes containing 40 grams of silicone sealant from Halfords made by Granville. These are probably the better option for casual users of silicone sealant.

Clean the aft face of the bumper and the area of bow that you will apply the bumper to using acetone or alcohol. Add masking tape around the area of hull that will have the bumper bonded to it. Allow the solvent to dry and apply a thick film of the sealant to the back of the bumper and a thinner film to the bow of the boat. Push the bumper onto the hull and carefully clean off the excess sealant. When the sealant has cured (leave for at least half a day) you will be able to peel off the masking tape.

Also known as a fender, bow fender.

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