If a signed document is in English is it valid under Brazil law?

We build sail boat masts in the US and ship to São Paulo, Brazil. In order to make sure the mast fits the boat we have a "Fact" sheet that the customer completes and signs confirming the information. These "Facts" are used to produce the mast so that it fits and will not break.

We have a customer who completed the "facts" and signed the document. We delivered the mast per the "Facts" but now the customer does not like the mast and tells us that since the "Facts" was not in Portuguese that the "Facts" is not binding and hence he wants a new mast.

Please advise if "Facts" need to be in Portuguese per Brazilian law.

Scott
Alexander