Any benefits to sealing pressure treated bunks?

[doyall]

Installing new pressure treated bunks on trailer and covering with glide wraps as shown on the attached picture. (Using SS lag screws, isolating the bunk from the mount with polypropylene sheeting and isolating the SS lag from the mount with fiber washers.) In the vein of (even more) overkill I wonder if there is any advantage/disadvantage to sealing the part of the PT lumber that will be underneath the wraps with polyurethane or paint prior to covering then with the wraps. I am thinking that *maybe* it will prevent the water that will inevitably get under the wraps from waterlogging the bunks by minimizing absorption as the normal evaporation process will be hindered by the presence of the wraps. I may be overthinking it but ...

 

[jcfitzgerald]

Re: Any benefits to sealing pressure treated bunks?

Installing new pressure treated bunks on trailer and covering with glide wraps as shown on the attached picture. (Using SS lag screws, isolating the bunk from the mount with polypropylene sheeting and isolating the SS lag from the mount with fiber washers.) In the vein of (even more) overkill I wonder if there is any advantage/disadvantage to sealing the part of the PT lumber that will be underneath the wraps with polyurethane or paint prior to covering then with the wraps. I am thinking that *maybe* it will prevent the water that will inevitably get under the wraps from waterlogging the bunks by minimizing absorption as the normal evaporation process will be hindered by the presence of the wraps. I may be overthinking it but ...

Treated lumber cannot be successfully painted with anything unless it is thoroughly dried, which takes months. Even then, once you get it wet again, any treatment will come off. I would leave it like it is and just cover it. I went to a plastics store and they cut me two 3-1/2 inch by 10 ft strips of 1/2 inch HDPE. Cost fifty dollars and enough left over from the sheet to do another. It sits on top of the wood, instead of enclosing it, and is fastened with recessed rustproof deck screws. I fastened the boards to the bunks with standard lag screws. The old standard plated lag screws had been in there about 13 years, and were rusty but not destroyed. I think you have a little overkill IMHO.

 

[Splat]

Re: Any benefits to sealing pressure treated bunks?

Is this a aluminum or fiberglass hull?

 

[doyall]

Re: Any benefits to sealing pressure treated bunks?

Is this a aluminum or fiberglass hull?

Fiberglass.

 

[bigdee]

Re: Any benefits to sealing pressure treated bunks?

I don't know because I have always used untreated and it lasts for years. I was thinking of using treated but what I looked at was crappy looking wood with lots of knots. Plus with the corrosion issues I do not see that big of an advantage. I replace the carpet 2 or 3 times before the regular woods rots.

 

[MH Hawker]

Re: Any benefits to sealing pressure treated bunks?

Most people use non treated wood for bunks, and those will last many years as is. PT wood is bad on aluminum but is ok on glass.

 

[doyall]

Re: Any benefits to sealing pressure treated bunks?

Most people use non treated wood for bunks, and those will last many years as is. PT wood is bad on aluminum but is ok on glass.

The original bunks were apparently non-PT and have started growing fungus (essentially rotting) after only six years. They may would last several more years before being unsuitable for further use but I am not fond of having the fungus get in my nose and eyes when I work under the boat. Hopefully the PT will not suffer the same malady.

Interestingly enough, the lumber I am using (PT using micronized copper azole compounds - Above Ground .06 PCF [rating?]; Treated Wood Process SCS-EPP-01699 [whatever all that means]) specifically states "aluminum building products may be placed in direct contact with micropore treated wood." It is "environmentally preferable," probably suggesting that it is not the 'good' stuff but hopefully better than non-PT. I will see.

 

[I_5320]

Re: Any benefits to sealing pressure treated bunks?

I've been spending a lot of time researching on my trailer rebuild.

Cypress comes out on top and is the preferred bunk wood of you can get it. I did find some in IL but it was $$. I hear is much cheaper in the South. I was a little softer than I thought it would be but it's a full 1 3/4 in thick.

 

[ONEGA]

Re: Any benefits to sealing pressure treated bunks?

Why don't keep it simple? I redid one of my old trailers last year: PT lumber covered with carpet, SS staples, SS bolts thru bunks and galvanized adjustable bolster brackets. Expect it to last for at least 10 years.